An introduction to the LFA-Q for 70Mhz.

A 4 element low-noise, High Gain LFA-Q Quad Style Yagi for 69.9-70.5MHz

MASSIVE Gain for a very compact boom size

Performance

Gain: 10.62dBi @ 70.2MHz

F/B: 25.34dB @ 70.2MHz

Peak Gain: 10.71dBi

Gain 10m above ground: 16.38dBi

Peak F/B: 25.88dB

Power Rating: 5kw+

SWR: Below 1.4.1 from 69.9MHz to 70.5MHz

Boom Length: 2.6m

Vertical Stacking: 3.75m

The LFA-Q (Loop Fed Array Quad) Low-Noise Yagi takes a lot of the good points from the LFA Yagi and adds some more. the LFA-Q is a quad with a difference. Rather than placing symmetrical square or triangular shaped loops in a Yagi configuration, the LFA-Q uses the LFA Yagi style loops to produce high levels of side suppression, the difference being every element is a loop rather than just the driven element.

The shape of the loops have been formed (compressed) until the short side sections are exactly 180 degrees out of phase with one another and therefore, a cancellation effect occurs in much the same way as balanced line feeder works. This means high levels of suppression to both the sides and the rear of the antenna can be achieved.

So if the LFA Yagi does this so well, why do something different with loops forming all elements? The primary reason is gain per meter of boom on a full wave element antenna can be much greater than on a half wave element antenna such as the LFA. This results in compact, high gain antennas which are constructed to stand some serious weather conditions!

Noble Radio NR-6N4. New 4m and 6m dual band radio.

Noble Radio NR-6N4 is a new 4 m and 6 m dual band radio. It covers 50.0 MHz to 52.0 MHz and 69.9 MHz to 70.5 Mhz Modulation is CW and SSB. Power is up to 20 W PEP. Price range is around $800(us). The news release does not say anything about availability date.

The key, but preliminary technical specification, are listed below but are also subject to change:

Receiver:

Down converting design

Dual Conversion: 1st IF: 10.7 MHz 2nd IF: 25 kHz

Sideband elimination using phasing techniques with digitally generated Quadrature carriers and Image

Reject mixers preceded by 15 kHz crystal roofing filters

Ultimate receiver bandwidth set by adjustable SCAF filters (two 8th order filters used. One for High Cut and one for Low cut)

Sensitivity: MDS = -130 dBm

Dynamic Range Figures: blocking: 110 dB, IMD (3rd Order): 95 dB

Selectivity: 500 Hz to 4 kHz adjustable with the SCAF filters. Ultimate attenuation of filters are 55 dB or better.

Transmitter:

Power: 20 W PEP

SCAF Filters can be used to tailor SSB Transmit audio.

General:

Synthesizer: DDS/PLL synthesizer with 10 Hz minimum step size. Tuning rate is variable depending on the Tuning Knob speed (Variable Speed Tuning - VST)

The low level 10.7 MHz IF signal is also brought out to a rear connector so that it may be used for pan adapter or SDR applications.

Memories: 

10 Memories per band

Supply voltage: 11.5 V to 14 V DC, approximately 3.6 A at full output power.

Dimensions: 203 mm (W) x 305 mm (D), including knob and heat sink, 95 mm (H), including feet

Weight: Approximately 1.8 kg

EI4FMG is back on air.

The computer on EI4FMG was locked up after an automatic update, the computer has been restarted and it should run normally again..

This happens every now and then, to fix all that is needed is to plug out and back in the computer, as this is not at my house I will need the site manager (Brian EI9GTB) to be free,  the next time I am up there I will plug in a timer and get the computer to turn off for about an hour each night between 5am and 6am, this should mean that the next time it locks up it should sort itself out by being shut down and turned back on..

HB9CV for 4m.

A year or so ago I bought the HB9CV from Moonraker, The antenna was easy to put together, but the instructions are not very clear, you have to work out yourself how to fix the driven element. Inside the terminal box is an air spaced 'beehive trimmer' - not seen one of these for years! The trimmer is used to tune the antenna to obtain best SWR. This I found quite straight forward. This antenna has a rear mounting bracket, which is fine, but the supplied clamp was poor and even when fully tightened the antenna keeps dipping down. The extension rods have to be tightened with the screws fitted, I still don't understand why this kit has extension rods, why couldn't they make it all in one piece?

The antenna is nice and light and will work well either as a base antenna or as a portable antenna, these antennas are of reasonable price but I have included measurements and a link to the “HB9CV” calculator site.

HB9CV Calculator.

World Amateur Radio Day 2013.

Each year the IARU Administrative Council selects a theme for World Amateur Radio Day (WARD) for the following year.  WARD takes place each year on April 18.  At the November, 2012 Administrative Council meeting the AC adopted the following proposal:  "The theme 'Amateur Radio:  Entering Its Second Century of Disaster Communications' was adopted for the next World Amateur Radio Day, April 18, 2013."

The selected theme for 2013 is an excellent opportunity for amateur radio emergency communications or disaster communications groups to take advantage of the WARD to highlight the role amateur radio plays in disaster communications and disaster response.  IARU member-societies could arrange amateur radio demonstrations in public places such as parks or shopping areas.  Prepared hand outs could explain the benefits of amateur radio in times of emergency or disaster.  A ham radio demonstration in public areas usually generates inquiries and questions from the public about amateur radio and it also provides a great opportunity to attract new ham radio operators.  If you plan on such a demonstration, don't forget to include some young people from your society so that young people who happen by the demonstration can see that amateur radio activity can be enjoyed by people of all ages.
In 2013, April 18 is a weekday.  However, that doesn't prevent the public activity from taking place on the weekend before or after April 18.  The idea is to gain as much exposure and publicity for amateur radio as possible.

If anybody is interested in participating or may have an idea for a location please contact the AREN team on the following email address:  arennortheast@gmail.com.

AREN (Amateur Radio Emergency Network) Jumps into action...

Wouxun KG-UVD1P/L Review – Worlds 1st 70/144 Mhz dual bander By GW7AAV.

I just could not resist the new Wouxun KG-UVD1P/L 2m/4m dual band handheld amateur radio, even though I have far too many portable rigs already. The fact that it was the only radio to ever be produced that was dual band and dual watch on these two bands might have swayed me, but I have become a bit of a fan of this companies products and I really wanted to see if my predictions on how their quality and range improves over time prove true.

Straight out of the box I saw the first improvement, a much better quality charger with a thirteen amp UK plug. Gone is the wall wart charger but so is the ability to use the charger from a cigar socket, it is no big loss to me as I have several of the old type already which I can use on long Raynet incidents or between SOTA activations. The look and feel of the new charger is a good improvement on the old ones, which seemed cheap, tacky and somewhat flimsy.

The antenna was taped to the outside of the box which seemed a bit strange but comparing the size of the rubber duck to that of the ones on the KG-UVD1P 2m/70cm rig and the Wouxun KG-699E it was somewhat longer. Surprisingly it is probably responsible for the improved receive that was the next advancement I found.

I was sat at my PC with the rig just out of the box and just called “GW7AAV testing” while listening back on my MyDEL ML-5189. Much to my surprise my pal Graham GW0HUS called me back. Graham is only 5 miles away but from the same position I could not hear him on the KG-699E. Several test calls later I am convinced that the KG-UVD1P/L is better on both receive and transmit on 4m that the KG-699E and on 2m than the KG-UVD1P. I believe this is only due to a more efficient antenna on both bands, but I have yet to test the theory by trying the supplied antenna on the other rigs. All the rigs have the now familiar reversed SMA antenna connection that had us scratching our heads when we first saw them.

Tests side by side using a Kenwood TH-G71E and a Yaesu VX-7 showed the new Wouxun to be better on receive than both the other rigs, using the supplied antennas. On TX very little difference was noticed but one station reported a little white noise on the Yaesu, and apart from that all stations reported the audio quality very similar. The Yaesu was the quietest, the Kenwood was reported as “just right” and the Wouxun a little louder, but not too loud. The Yaesu had me almost shouting, the Kenwood talking normally and I found I could double my normal distance from the mic with the Wouxun and still be easy to read.

Do not think that I am basing my tests on the S-meter readings either because like its predecessors it reads S9+ or nothing, whatever the signal. In fact the only time I ever saw the S-meter read somewhere in between was when I had some desensing from a nearby commercial transmitter on a SOTA activation.

The build quality of the Wouxun rigs is better than most of those emerging from China but as these are new rigs in the same case as the 2m/70cms version there has been no opportunity to improve the look. To be really picky the plastic of the case feels good but looks a little too shiny. It might not look as tacky if it had a matt finish.

For those familiar with the Wouxun range the controls should be no problem, but the same old issues remain with this rig as the others in the stable, it is a pig to program memories from the keypad. It is however an absolute doddle to do if you have the computer programming cable, which is very cheap to buy and works with Kenwood handies too. It was easy to import my settings in to the software from the 2m/70cm rig delete the 70cm settings and add the channels for 70MHz in their place. I saved the result with a new file name and I imported it in to a use with the new rig. It all took five minute start to finish. Using the keypad would have taken days.

Over all I am impressed, I was not expecting any improvements over the other Wouxuns, I just wanted to be able to carry one rig less up the hills. Previously Helen and I both carried a 2m/70cm KG-UVD1P rig on the hills and I also carried the KG-699E for 4m. This way I can replace my two rigs with one, Helen and I can still communicate on 2m and we can still cover the three bands. I still have the Icom 23cm rig and the Yaesu FT-857 in the rucksack though.

I wonder who will be the first to come up with a good 2 and 4m antenna for SOTA and portable or mobile or even home base?

Pros:

* No one else makes a rig that does these two bands

* Price.

* Excellent RX audio quality.

* Great RX sensitivity.

* Better immunity to out of band desensing than some more expensive rigs.

* TX audio reported by several people as very good.

* Solid feel and high quality construction almost as good as Japanese rigs.

* Desktop charger supplied with 13amp plug rather than the wall wart

* Very cheap batteries and accessories.

* Clear LCD display.

* Enough memories to never have to use the VFO.

* You can name the memory channels easily with programming cable.

* Cheap programming lead and free software.

* Lighter than my other (Japanese) handhelds.

* CTCSS decode/counter function.

* Voice announcement of functions (if they don’t drive you nuts).

* Narrow TX & RX FM mode available.

* Good battery life.

* Good belt clip.

* Supplied rubber duck works surprisingly well.

* LED torch (Great for finding the fuse box when the lights go out).

* FM radio for when no one is talking to you.

* Stop watch. I almost forgot this one because I only used it once.

* Cheap and easily available accessories from dealers or direct import (eBay).

Cons:

* Build quality is not quite what we get from the Japanese manufacturers.

* The out of the box wideband nature could lead to problems for those who don’t know their band plan. Tip: use memories for the ham bands and the VFO for out of band listening or use programming software to lock down to just the ham bands.

* Turning repeater shift on for the first time can be ‘tricky’, but once learnt, it’s not difficult. Tip: Read the manual or use memories.

* The S-meter reads full scale even on weak signals.

* Hard to understand manual.

Note: One or two people complained on the net previously that they could not get the USB driver that comes with the Wouxun software working with Windows 7. That would be because you don’t need it with Windows 7 due to USB support being built in. It is no wonder folk screw up their computers; they just don’t know what they are doing. If all else fails read the manual!

For the rig specs see this post: http://www.cqhq.co.uk/2011/06/wouxun-kg-uvd1pl-2m4m-full-dual-band.html

How good is your rubber duck antenna?

Have you ever wondered about the rubber duck antenna that came with your very expensive handheld???

Me neither, that is until today, it is lashing rain outside,windy and generally miserable, you know the type of day that you do not want to go out but you still need something to occupy your mind!!!

Well I decided to have a look at some of my rubber duck antennas to see which gives the best SWR and hopefully the best performance on my hand held's.

Now as not to pick on only the cheap antennas that I bought from a shop in Hong Kong I have also tested an Icom and Kenwood dual band rubber duck antennas that came with their radios.

Have a look at the photo attached, enlarge it and see the results under each antenna, the test was done on 5w on 2m and 70cms, the 2m frequency was 145.400 and the 70cms frequency was 433.400.

Shocked??? I was.......

Click on photo to enlarge.

AKD 4001 - 70 Mhz (4m) FM Transceiver.

Ascom SE550 on 4m 70mhz PA4DEN.

Anytone at-5189 4m, 70mhz ham radio transceiver Review.

MB7FM 4 meter 70mhz simplex repeater demostration.

This works the same as the Cork Parrot repeater or "Simplexer" on 70.350Mhz, also EI4FMG can also be put on this mode, this is very handy for 2 stations who are out of simplex range of each other,they can then work each other on the same frequency.
This is always handy if you are doing tests on your radio equipment and want to know how your audio is, etc...
If you would like the DTMF code to activate the Parrot on EI4FMG please email me.

Norway expands 4 m band.

Norway expands 4 m and gets "200"

Published on 6 November 2012 by Tom LA4LN

As of 31 October 2012, the Norwegian P & T Authority has made changes to the Norwegian amateur license regulations. The major changes are:

1.  Permission has been given to use 472 - 479 kHz (max. 100 W transmitter power output; max. 1 W EIRP). Hence the former permission to use 493 - 510 kHz has been stopped.

2.  Permission has been given to use 70.1875 - 70.2625 kHz, EXCEPT in the three Norwegian southwest counties of Hordaland, Rogaland and West-Agder, where there still is commercial traffic within this frequency segment.

NRRL had argued that the bulk of Norwegian radio amateurs should not be barred from using the IARU Region 1 calling frequency on 70.200 MHz and vicinities, because of a few commercial stations in the southwest corner of the country. This reasoning has thus been accepted by the Norwegian P & T authority. Hence the permission on 4 m with max. 100 W transmitter power, and max. 16 kHz bandwidth, include the following frequency segments:
70.0625 - 70.0875 MHz
70.1375 - 70.3125 MHz*
70.3625 - 70.3875 MHz
70.4125 - 70.4625 MHz
* 70.1875 - 70.2625 MHz not permitted in the counties Hordaland, Rogaland, and West-Agder (southwest Norway).

My Yaesu FT-847 is for sale!!

I am selling my Yaesu FT-847,Covers the following bands:
HF, 6m, 4m, 2m and 70 cms. AM,FM,USB,LSB and CW.
Also with the radio is an Icom SP-21 external speaker,
operators manual and box…..
Nice clean radio and can be seen anytime at my QTH, try before you buy!!!

Price €1000.00 ono .

ICOM HF rigs with a Spectrum TRC4-10L Transverter by Alex GD3UMW.

Spectrum TRC4-10L.

I am new to 4 metres. In March 2009 I hoped I could buy a transverter, plug it in to
my HF rig, connect an antenna and have a smooth, no fuss entry to 4 metres. I
wished to use an existing rig with all the features I found routinely useful on HF like
multiple modes, dual receive, spectrum analyser and receive filters. It had to be
already built. Life is too short for homebrew or kits at my age.
My essential requirement was to have one switch to toggle the system from HF to 4m
and back again while retaining all the connections to the HF antennas, amplifiers, rig
control and accessories. Hard wired changeover from the HF rig was preferred
Some manufacturers offer built transverters for HF rigs but none are plug-and play.
None offer protection from accidental high levels of HF power from 100 Watt rigs
when swapping RF connectors to go from HF to 4m and back again. Accidents happen
and can be catastrophic. Patch cables and switching had to be made. It is all beyond
many of today’s hams. I am sure many potential users of 4 metres have been put off
by this situation.
The transverter with the nearest specification to meet my needs was the Spectrum
Communications model TRC4-10dL. It is a low power drive transverter with up to 25
watts output on 4 metres and good receive performance. With minor work I could get
it to interface with my ICOM 756 PRO II.
The IC735, 756, 756PRO, 756PROII, 756PROIII, 761, 765, 775, 7600, 7700 and 7800
have a dedicated low level drive connector therefore cannot burn out the transverter.
Applying a voltage between 6 and 8 volts to pin 6 of the Accy 2 socket puts all the rigs
listed into XVERT mode and isolates all the HF power circuits. Other ICOM rigs do not
have a low level transverter output and are not compatible with this transverter
modification except the IC751 which would only need a different patch cable.

Rear View of the modified TRC4-10L.

There are few differences between the Spectrum models. One coax socket is used for

the higher power sL version and separate Rx and Tx sockets for the low power drive

dL model. Builders may wish to add the modification to existing kits before final

assembly. Refer to the documents to go through the mods listed below

For personal convenience I wished to set the ICOM power control to the same position
for both full transverter output and driving my HF amplifier to 400 Watts output.
Changing one resistor on the main board achieved this. The Tx-Rx control is hard
wired. I disabled the RF switching circuit and reduced its hang time by removing one
capacitor and changing another.
Mod List
 Change main board resistor R6 to 1k5 and capacitor C17 to 4.7 mmF
 Remove main board C2 to disable the RF switching circuitry.
 Remove the short coax cable from the RCA jack to main board pins.
 Move the coax cable from the SO239 socket to the RCA phono socket.
 Remove the SO239 socket.
 Fit a 7-way DIN single hole socket in the hole left by the SO239.
 Refit the SO239 flange screws and nuts after the DIN socket is fitted
 Connect two 1k5 resistors in series between J9 and J2. Connect the mid point to
pin 6 of the DIN socket This provides a XVERT enable voltage for the rig.
Alternatively connect one resistor between pin 6 and pin 2 and another from pin
6 to a hook up wire connecting to J9 on the main board. Whatever is neater.
 Add short equipment wires from the 7-way DIN to the main board terminal pins
between pin 2 and J2 (ground) and between pin 3 and J10 (send)
 On the main board remove R3 if fitted and fit C1 if not fitted. (sL or dL versions)
 On the main board restore the cut track if the dL version.

Internal View showing the new wiring.

Tie wraps keep the new wires tidy
Connection between transceiver and transverter requires a short coax cable with RCA
phono plugs each end and a screened cable with 7-way DIN plugs each end wired 2-2,
3-3, and 6-6.

The Patch Cables –other cables omitted for clarity.

A simple, once-only, setup for maximum power level is described in the TRC4-10
documentation and requires the main board potentiometer RV1 to be adjusted to give
25 Watts output when the HF rig drive control is set where required and the TRC4-10
front panel power control is at maximum. Please note you can overdrive the
transverter and create a lousy signal but you cannot overdrive it to destruction.
The transverter now runs 25 watts when its front panel control is set to maximum and
the ICOM power control set to about 50 percent. The combination of ICOM 756 PRO
II and Spectrum transverter gives operation on CW, SSB, FM and Data modes. Even
AM is available for the dinosaurs. If these simple changes were made available by the
manufacturer it should attract more HF people to 4 metres who are good operators
but not blessed with the needed technical skills or those who believe that “life is too
short for home brew”.
Alex Gartshore GD3UMW
I asked Spectrum Communications for comments on this article before submitting it
and if they would consider requests to build this model as a special. I was pleasantly
surprised to receive an enthusiastic reply that a unit with this specification will be
added to their product line and designated TRC4-10L-ICOM. The package will come
fully assembled, calibrated and set up for use with the ICOM rigs listed above
including the patch cables. The choice of 4 metres or HF is made by toggling the
transverter power switch on or off. A true plug and play solution.

New ICOM IC-7100 transceiver with 70 MHz.

ICOM IC-7100 (Click for larger photo)

The IC-7100 is a HF, 6m, 4m, 2m and 70cms all mode compact radio with an innovative slanted touch-screen LCD controller. A first for an Icom transceiver, the IC-7100 is designed to the 70MHz band in European versions where 70MHz is open to Amateur radio enthusiasts. To maintain its commitment to D-STAR, all versions of the IC-7100 will come with standard D-STAR DV mode.

Since the launch of the original IC-706 in 1995, Icom has been leading the market of HF/VHF/UHF multi-band mobile radios. The popularity of vehicular mounted amateur radios may not be as high as the times of the IC-706 series, but the IC-7100 has been carefully designed to reignite Amateurs’ interest in mobile communications and brings digital communication opportunity to a wider range of radio Amateurs.

Planned Features include

• Slanted front separated controller with large touch screen dot matrix LCD (controller cannot be attached to body front)

• Speaker is self-contained inside the controller

• Full mode (SSB, CW, AM, FM, RTTY decode) and D-STAR DV

• HF (100W) / 50MHz (100W) / 70MHz (50W) / 144MHz (50W) / 430MHz (35W) (Note: Power may be different according to version. The 70MHz band is available for some versions only)

• Lower current consumption / cooler operation (compared with the IC-7000)

• SWR meter function also works for VHF and UHF bands

• Remote power on / off

• IF DSP for filtering / interference removal / noise reduction

• SD memory card slot, voice recording

• USB Audio In / Out, remote control

• +/- 0.5ppm frequency stability

• 505ch memory channels

I have been a bit side tracked lately!!

I have not been too busy on 4m, I got myself a bit side tracked with AREN:

AREN stands for Amateur Radio Emergency Network. It is a Public Service Voluntary Radio Emergency Network run by The Irish Radio Transmitters Society (IRTS) in co-operation with ComReg, the licensing authority. It was sanctioned following Ireland’s adoption of Resolution 640 (1979) of the Radio Regulations of the International Telecommunications Union, which provides for the utilisation of Amateur Radio communications in emergency situations. The Irish Radio Transmitters Society is the National Society for Radio Experimenters, and is the member society for Ireland of the International Amateur Radio Union (IARU).

Previously, Irish Radio Amateurs were licensed to communicate only with other Radio Amateurs nationally or internationally, however, the ComReg Regulation now extends the License Terms and Conditions of AREN operators to permit them to pass the third party messages of the designated Emergency Services listed below.

Fire Service

Civil Defence

Garda

Mountain Rescue

Health Service Executive

Voluntary Ambulance Services

AREN is not an alternative to any existing Emergency Service but, rather, a reserve communications resource included in Major Emergency Plans that the served agencies may call on as required.

In an Emergency, AREN shall come into operation if requested to do so by an incident Controller of Operations or a Senior Official of a designated Emergency Service. It shall function under such control in order to meet the radio communications needs of that service for the required duration.

Situations when AREN can be of Assistance.

During times of prolonged emergency when existing communications links are overloaded or in danger of failing due to human or equipment fatigue.

During major disasters when normal communications links are saturated.

When short-term communication difficulties arise beyond the scope of existing systems, such as, an incident in a communications ‘black spot’ or a system failure.

To enable radio communication between different Emergency Services.

During public and sporting events when additional communications resources dedicated to emergency and safety requirements are desirable.

Search and Rescue Training on Bettystown Beach in County Meath.

AREN Control with Seamus EI3KE in Ardgillan Castle grounds,Skerries,County Dublin.

Dressed up!!

AREN North East team:( L-R), Thos-EI2JD, Ben-EI4IN, Sean-EI4IP, Anthony-EI2KC, Seamus-EI3KE, Derek-EI7CHB, Myself Tony-EI4DIB and Pat-EI2HX.

View from site of EI4FMG.

Click on photo for bigger image.

Here is a photo taken today from where EI4FMG is located, the computer, radio and interface is in one of the smaller buildings and the antenna is on a 2m pole on the chimney of the house.
You can see that the location has a nice take-off.

The Icom IC-E90 Tri-Band handheld on 4m.

The IC-E90 is a tri-band FM handy designed to operate in the 6m, 2m and 70cm amateur bands. For some while there has been interest in a modification which would allow these sets to work in the 4m band too.

A modification published on-line a couple of years ago merely described how to remove the out-of-band inhibit function, so allowing the set to transmit and receive at 70MHz. This took no account of spurious outputs from the transmitter, and one correspondent had interference problems reported by local military air traffic control!

Happily, one of the major UK dealers can now supply these sets ready-modified for 4m use with the inclusion of a filter to reduce spurious outputs, although they can only achieve a second-harmonic suppression of around 33dB, so it is not advisable to use the rig into a external antenna or amplifier without additional external filtering. 

International Space Station Contact to be relayed live via EI4FMG.

ARISS contact planned with ESA Space Camp in Dublin, Ireland.

Sunday 22 July 2012, at approximately 17.25 UTC, which is 18.25 Dublin time and 19.25 CEST, an Amateur Radio on the International Space Station (ARISS) contact is planned for ESA Space Camp in Dublin, Ireland.

This will be relayed live through EI4FMG at the times above.

The European Space Agency has locations in several European countries. The annual summer space camp is an occasion when the children of staff employed at ESA get a chance to mix with each other in an environment which allows them to be immersed in space activities and cultural events.

This year the 160 ESA campers will land in a traditional "Harry Potter” style boarding school near Dublin, in a country full of mystical stories and a breath taking landscape, on 14 July 2012. St Columba’s College offers the amenities where children will learn about Space Ship Earth in more detail, with emphasis on hands on activities and having fun whilst learning.

As part of their 2 week stay at the camp, the children aged 8-17 years, will take part in sporting events, field trips where they will explore more about what earth is made of, look more closely at how we explore other planets and design their own launchers and space suits. They will be visited by an ESA astronaut who will join in the activities and explain about astronaut training and human spaceflight.

The space talk will be a telebridge contact operated by W6SRJ, located in Santa Rosa, California.

ARISS is an international educational outreach program partnering the participating space agencies, NASA, Russian Space Agency, ESA, CNES, JAXA, and CSA, with the AMSAT and IARU organizations from participating countries.

ARISS offers an opportunity for students to experience the excitement of Amateur Radio by talking directly with crewmembers on board the International Space Station. Teachers, parents and communities see, first hand, how Amateur Radio and crewmembers on ISS can energize youngsters' interest in science, technology and learning.

Yaesu FT-847 70 MHz Pre-amplifier By Tony CT1FFU.

Last Spring I decided to buy a Yaesu FT-847. Using an all mode all band radio, operation becomes much easier and give better accommodation on shack however, I soon got frustrated with its reception as the signals were much weaker then the ones received with my home-made X-verter (dx-70-G4DDK design).

I decided to look on web for a modification and Marc's, PA1O BPF, was a good to start. Marc’s article, convinced me with the good results on filter modifications as well as the simplicity of those changes. After Marc’s modification the radio became better, but still not with a satisfying RX performance . FT-847 has a build in preamp, but it seems to have poor gain at 70mhz, so I decided to add another preamplifier stage.

I have looked carefully on circuit diagram trying to find the right place to insert a amplifier which wasn’t however easy, but I realise that the band-pass-filter, a Chebyshev, could be rearranged and have the preamplifier inserted there . Results were clearly better as sensitivity is concerned and in many comparisons with transverter it was easy to see the improvement.

After I published a small article on www.70mhz.org these modifications were reproduced with success by others. The results are good and hundreds of boards are now installed world wide on FT847s Later, as per many requests, I decided to make a KIT available. This KIT is very easy to install and anyone with a bit of radio/electronics experience can do the job easily.

Laboratory tests made by GI0GDP and CT1BXT shown that once fitted the pre-amp the 70mhz RX achieve similar sensibility as on 50 MHz, even without PA1O BPF modification.

The design.

I decided to use a MAR6 (MMIC from MiniCircuits) because of it’s 50 ohm impedance; stable amplification, 22dB
gain and noise figure low enough for the application. This amplifier uses the typical configuration and bias and is placed in the in the BPF which was rearranged as seen in fig1.

Brief performance of the FT847 after preamp fit.

Since the radio has some 1.5 dB loss on the PA filter and still some more few dB in the subsequent HPF filter on the daughter board the lowest NF achievable is still quite limited by those factors. NF at 70 MHz is now about 7 dB (note the 15.5 dB NF the radio had originally) which makes perfect sense taking in consideration the circa 2.8 dB NF of the MAR6.

Using a lower NF device would bring just a bit better NF but as per the loss limitations described above, without further changes into the radio, performance would not get much better than this by improving the preamplifier alone. This 7 dB NF could be also expressed as a sensitivity of about 0.1 uV for S/N of 6 dB at 2.8 kHz BW.

Preamplifier with surrounding existing components:

Schematic of the add on board:

Amplifier design with MAR-6:

PCB design:

Best 73’s CU on 4m
Tony www.ct1ffu.com

AKD 4001 is a low cost rig specifically designed for use on 4m.

Here is a nice little basic radio for 4m, The AKD 4001 is a low cost rig specifically designed for use on 4m. In the past 4m operation was obtained by either modifying ex AM PMR equipment or buying expensive transverters - some of which are no longer available. The rig comes with a useful  25W on high power, 5W on low power. Powered from an external 13.8V DC supply, it can either be used as a mobile or base station rig. Supplied as standard with a fist type microphone with 4- pin mic. connector and DC power lead.
The buttons on the front of the radio are self explanatory, "On/Off" turns on and off the radio, "Lo/Hi" is the output power of the radio, and the channels are changed by the right and left arrows. The usual Squelch and Volume knobs are there too!!
Channels are displayed as numbers (not frequencies), see the chart below for corresponding frequencies and channels:  

The down side for this radio is that it only covers 70.250-70.4875 MHz (20 channels/12.5 KHz spacing) also does not have CTCSS.
See below for a chart of frequencies for the AKD 4001:

Pye A200 Linear Amplifier for 4m.

The A200 is a 'stick it in the boot and forget it' add-on linear amplifier. Not many amateurs realise that PMR equipment of days gone by could sometimes do with a few extra watts when trying to achieve the maximum in range. Improvements in base station receivers, coupled with the ever-increasing need for spectrum re-usage, has meant that these units are increasingly finding their way onto the amateur market. Inside these sturdy weatherproof boxes you will find a piece of mint-looking board with a 50W-plus linear amplifier, complete with automatic RF sensing and change-over switching. Just the job for 2m, 4m, or with some modifications, 6m.

Identification:

The A200 is easily identified as a solid die-cast unit with heat dissipation fins on its topside, and are always painted black. It always has three connections at the end, these being RF input, output, and a thick DC power lead. The only similar-looking unit around has the same outer case but with two thick d.c.leads coming out of the side, this is a type VR200 24V-to-12V converter, so don't be misled by appearances.

There have been two types of A200 in manufacture, an early model having a TNC RF input socket and an N- Type RF output socket, and you may sometimes find a later model, with one S0239 output socket and a flying co-ax lead for the RF input. Internally they are virtually the same, but you may find the later model arrangement is easier to install. The DC cable is actually a very heavy current AC cable, with brown, blue, and green/yellow leads - brown is used as the positive 13.8 V supply, blue as negative, and green/yellow as a switching lead, but please don't wire it up to your mains plug as the capacitors inside make a lovely exploding noise!

Selection:

On the side of the case, you will find a riveted plate with "Cat No. A200" marked, and below this is space for the aligned frequency of operation. Unfortunately this is often blank, but take a look at the section marked "Code", you will see something like "01 E0", which provides the frequency band information. The first two numbers are the market code, which is irrelevant for our purposes, the final letter/number combination gives the frequency range:

EO: 68-88MHz,

M1: 105-108 MHz,

BO: 132-156MHz, and

AO: 148-174 MHz.

The E0 is useful for 4m, and both the B0 and A0 models will tune to 2m. The E0 model will also, with the modifications described, operate very satisfactorily on the 6m band.

Circuitry:

Internally, a pair of MPX085P or BLW60 transistors are used, which have forward bias applied via a wirewound resistor and two forward-biased diodes. Input and output printed circuit inductors together with compression trimmers and a three-stage low-pass filter are used in the RF path, a further capacitor and plate resistor on the input form a gain control to ensure the amplifier is operating in the linear portion of its input/output curve. RF sensing circuitry detects input drive, and switches in the amplifier if DC power is supplied. The unit is extremely rugged both physically and electrically, and even incorporates an over-temperature cutout to stop the transistors overheating in use. I have never yet seen a faulty amplifier sold, but it would be wise to check inside to ensure there are no components that have obviously been removed.

Preliminaries:

Check that the internal pins are correctly linked, with pins 2 and 3 connected together, and pins 4 and 5 connected together. This will ensure that the RF sensing circuits will always be powered up, ready to switch DC to the amplifier itself via the internal DC relay when RF is detected. If you wish to use a small toggle switch for on/off switching however, make sure both of these links are removed and then use a switch between the green/yellow DC wire and 0V to connect the amplifier into circuit. When not switched in, RF input and outputs are simply linked for a 'straight through' connection. Connect up your DC supply, with positive to the brown wire, negative to the blue wire on the thick power lead, ensuring your power supply has the current capability required. As a guide, a 10-15A 13.8V supply will be required for maximum output with a 10W nominal drive power. Connect up your transceiver to the RF input connection, and a suitable load capable of handling 60-70 W to the RF output. If your A200 has a TNC input connector, you may find it more useful in practice, to remove this and replace it with a coax lead, terminated in a PL259 or BNC as appropriate to suit your transceiver.

Tuning:

Alignment to 2m or 4m is extremely simple. Initially set C7 for minimum capacitance, i.e. its vanes fully apart. This is used as an 'RF Gain' adjuster, to reduce the input drive power to the amplifier stages. Whilst transmitting 2W-15W of RF power into the unit, check that the relays click over, and simply tune C8 and C17, both for maximum power output, re-tuning as required until you cannot achieve any further increase. If you have an in-line SWR meter, you may like to insert this in the co-ax between your transceiver and the A200 amplifier, and re-adjust C8 slightly as required for minimum indicated SWR, this should coincide with maximum RF power output.

You will typically get around 50-60W output for 10-15W input, with less than this of course with reduced input drive. If you intend using the amplifier on AM (see later for SSB), then it is important now to adjust C7 until you reduce the output power to around 25 W. This will ensure the amplifier will handle the positive peaks of modulation presented to it from your transmitter.

SSB Modifications:

As the A200 is a linear amplifier, it will of course handle SSB quite well. However, as it was originally designed for remotely mounted AM/FM use, as soon as the RF power falls below a given level the amplifier relays cut out, and as a result, use on SSB causes a good deal of relay 'chattering' and broken transmissions. We may add a suitable 'hang time', i.e. a switch-off delay, by adding a small - electrolytic capacitor across C2 and C3. A value of 0.68μF will give - around three-quarters of a second delay which I have found is the most acceptable, 0.47μF gives around a half second, and 1μF around one second. Any capacitor of at least 10V working voltage will suffice. Fit the capacitor with its positive lead to the D2 cathode/R3/C2/C3 junction and with its negative lead to the PCB ground plane.

You may also find it useful to increase the RF switching sensitivity, to prevent losing the first syllable of speech following a pause in transmission. To do this, fit a small ceramic capacitor of around 4.7pF in parallel with C1 on the A200, this will increase the RF detection sensitivity to below 50mW. Both of these additional capacitors may easily be soldered to the component side of the PCB, hence removing the need to extract the main board from the chassis.

Following this, tune the amplifier as described with C7 at minimum capacity. Once this has been done, adjust C7 so that the output RF power decreases by approximately 10%, this will ensure you are not overdriving the amplifier and that it is operating in the linear portion of its transfer characteristic. After doing this, you may find that you need to slightly readjust C8foroptimum output power. As a guide, you will typically achieve around 45-50W PEP power output with 28 dB rel. PEP level 3rd-order IMD products. Don't try to squeeze the last drop of power out on SSB, this will degrade the linearity of your signal, resulting in audio distortion and splattering across a wide bandwidth.

EI4FMG Audio sorted.

I was up at EI4FMG site yesterday evening and now have the audio sorted, both the RX and TX audio are now at a level that are not distorting, also I now have remote access to the computer that runs EI4FMG and I can now adjust any audio settings from my home QTH, this will make things very handy for me in the future.
At the minute live streaming via the internet is not available but should be back up and running over the next while.
Ongoing tests are showing that the gateway has a far better coverage that what we hoped for..

Do not forget,Node number: 57006, frequency is 70.350 NFM simplex and CTCSS is 88.5Hz, without the CTCSS you will not be able to get through the gateway..
For those connecting through a local gateway on 2m, 70cms or even HF, just dial 57006 with your DTMF Microphone to connect direct to EI4FMG.....

EI4FMG on air in permanent location.

Finally EI4FMG is now up at it’s permanent location in Fieldstown, Monasterboice just north of Drogheda in County Louth, and what a location!!!!

I still have a few “tweeks” to do with it’s audio in that the audio coming in from the internet is a little too strong, so I will have to visit the site soon and sort that or see if I can adjust it remotely.

So far there has been a great response to it’s first day up there, the range is fantastic, for example: John, EI4L in Celbridge in County Kildare had no problem getting into it, Jim EI2HJB/M from outside his house in Blackrock, County Louth and Aidan GI7FHC in Newry was very strong into the gateway. Also Pat, EI2HX was mobile 10 Km south of Omagh when he started hearing EI4FMG giving it’s ident.

I would like to thank all those who helped in the setting up of EI4FMG, Richard – MI3CQR who’s expertise was invaluable and Brian – EI9GTB who’s property that EI4FMG is now running from and to all who donated time and equipment to it’s construction.

Please feel free to use EI4FMG as often as you like, log on via computer or mobile phone and have a chat with all the local 4m hams, for those connecting via radio please note that the frequency is 70.350 MHz FM and a CTCSS of 88.5 Hz is needed.

ME4T-PRO 4m LINEAR TRANSVERTER.

Here is an item I came across while browsing the net, have a read and see what you think!!

 ME4T-PRO  4m  LINEAR TRANSVERTER

• Frequency Coverage: 69.9-72MHz band.

• IF in/out Frequency : 27.9-30MHz

• LO frq stability: Low phase noise TCXO, Better than +-1ppm 0-+50C,• I/O Impedance : 50 Ohm unbalanced – coax jack UHF type.

• Input Voltage : 13.8VDC, +-10%, polarity mismatch, 10A -40dB EMI filter.

• Power Consumption : 0.36A RX, 5A TX @25W output.

• Size & Weight : WxDxH: 240x210x70mm, 1.5kg.

RECEIVING SECTION

• RX front-end : 27dBm OIP3, ASB ALN0070WT LNA

• RX RF mixer : MCL SRA-1H, +17dBm

• RX overall gain : max. 22dB variable

• IF rejection : >85dB

TRANSMITTING SECTION

• Power Output: 30W continuous carrier.

• IF power input: -10 to +37dBm (switchable built in att.) Single or two IF cable operation.

• SWR input : 1:1.1

• Emission modes : CW, SSB, FM, FSK.

• Harmonic Output Suppression: Better than 60 dB below rated output.

FEATURES

RA30H0608M Mitsubishi RF Power Module

Built in ext. fan speed controller circuit

LED bargraph Power meter

Output PWR poti on the front page (5-30W)

SND jack for ext PA’s (GND out when TX, open collector +50V/0.5A max)

ALC circuit

Optional fan module (2pcs 50x50mm external fan on holder plate)

Optional +30dBm RX mixer

Built in heatsink temp. sensor

IF input & output BNC connectors

20A type DC connectors

Optional IF RX, TX and PTT cables

DC output to ext. preamplifiers

• Operating environments:

- temperature range: 0…+50 degs.Celsius;

- humidity: up to 95% @ +35 degs.Celsius.