Saturday, 27 June 2015

Simoco SRM 9000 Revisited

A while ago I blogged about my 3 Simoco 9020's in the boot of my car, above you will see the 2m, 70cms and the 4m ones.
Sadly that car has gone and the 4m radio has found a home in my new car with a 9030 head on it, the 70cms one is in my shack and the 2m one is on loan to a local ham.

Recently I decided to take one of the radios apart to have a look at the magical stuff inside, I will not even try to explain what goes on, it is all witchcraft to me!!!!

Above the Simoco SRM9000 complete in it's "shell".
Below you will see an "E" band (66-88Mhz) radio out of it's shell.

Here below the BNC and power/extension speaker socket. These radios, like a lot of PMR radios do not have internal speakers.

Below again you can see the microphone/remote head socket.

Here below are two photos of the main board, plenty of surface mount technology, too much for me to understand!!!!

Thursday, 25 June 2015

Back mobile on 4m…..

Hi all. At long last I am back up and running on 70Mhz mobile. Using the trusty Simoco SRM9000 with the remote Simoco 9030 head. I have the radio programmed up with the whole 4m band in 12.5Khz steps and also have the gateways and links put in using the callsigns (CTCSS for each on as well).
The radio runs 25 watts on high power and 5 watts on low power, also have scan, squelch level as well as DTMF on it as well, basically all you would need on a radio, and of course it has the signal meter which is handy.
I am running the radio on a ¼ wave 4m antenna at the minute but plan to get a 5/8 wave in the future..
Also in the car I have the Wouxun KG-UV950 which operates on 10m, 6m, 2m and 70cms….

Listen out for me /M. I will be scanning…….   J

Tuesday, 23 June 2015

FCC Turns Down Petition to Create a 4 Meter Band in the US

It does not appear that US radio amateurs will gain a new band at 70 MHz anytime soon. The FCC has denied a Petition for Rule Making filed earlier this year by Glen E. Zook, K9STH, of Richardson, Texas, seeking to add a 4 meter band to Amateur Radio’s inventory of VHF allocations. Zook had floated the proposal in 2010, and his petition was dated January 27, 2010, but the FCC said it did not receive it until last May. Zook asked the Commission to allocate 70.0 to 70.5 MHz to Amateur Radio because, Zook’s Petition asserted, “the recent migration of broadcast television stations to primarily UHF frequencies basically eliminates any probable interference to television channels 4 or 5.” VHF TV channel 4 occupies 66 to 72 MHz.

“Because the Zook Petition is based on a faulty premise — that broadcasting use within the 70.0-70.5 MHz band will diminish or cease — its argument that amateur band users could operate without causing harmful interference to any existing service lacks sufficient support to warrant our further consideration, The FCC said in a September 17 Order denying the Petition.

The FCC pointed out that three full-power TV stations, 110 low-power TV stations and translators, and six Class A TV station now occupy channel 4 in the US. In addition, the Commission, through an “ongoing incentive auction proceeding,” is attempting to “repurpose” a portion of television broadcast spectrum for broadband operations and “repack the remaining TV stations into a smaller frequency range.” Under certain scenarios, the FCC said, channel 4 could become even more heavily populated by broadcast users in the future.

“Given the complexity of the of the incentive auction proceeding, we also conclude that it would not serve the public interest to further complicate that unique undertaking by proposing to introduce a new service into the broadcasting frequencies at this time,” the FCC said. The Order noted that fixed and mobile services will continue to operate in the frequencies between channels 4 and 5 (76 to 82 MHz).

As Zook noted in his petition, a 4 meter band has been authorized for Amateur Radio use in the UK and in a number of other European and African countries. The FCC said that since it wasn’t planning to grant Zook’s petition, it declined to evaluate his claims “regarding the benefits that amateurs would derive from use of the band.” Zook’s original proposal asked to have the FCC open up the allocation to all classes of Amateur Radio licensees.

Brian Justin, WA1ZMS, operated an Experimental Service beacon transmitter from Virginia on 70.005 MHz under the call sign WE9XFT. At the time his Experimental license was granted in 2010, Justin told the ARRL that he was not seeking to have the FCC create a 4 meter band. “This beacon is purely for radio science for use as an E-skip detection device,” he explained.

Saturday, 20 June 2015


The philosophy behind band planning is that it assigns frequencies for certain activities in such a way that all current users can practice the various modes of amateur radio with a minimum of mutual interference.

The 70MHz UK band plan is based on the International Amateur Radio Union (IARU) Region-1 band plan.

The plan shows the frequency limits of individual ‘sub-bands’ or segments. The allocation of sub-bands enables the indicated category of users to employ any frequency within that sub-band provided that no appreciable energy falls outside that sub-band. Users must therefore take into account the bandwidth of their sidebands when selecting an operating frequency.

The ‘Transmission Bandwidth’ determines the maximum spectral width (-6 dB points) of all emissions recommended in a sub-band. The mode indicates the modulation methods (e.g. telegraphy, telephony, machine generated mode) allowed in a segment. A machine generated mode (MGM) indicates those transmissions relying fully on computer processing, for example FSK441, JT6M, JT65, PSK31 or RTTY.

The ‘Usage’ column indicates the main usage of a sub-band or segment. It contains meeting/calling frequencies agreed upon for the convenience of the VHF operators practising specific modes of communication. These frequencies are not part of the adopted 70MHz IARU Region-1 Band Plan and although in the normal amateur spirit other operators should take notice of these agreements, no right on reserved frequencies can be derived from a mention in the usage column.

This area of the band is allocated to beacon stations with a maximum transmission bandwidth of 1kHz. This section also accommodates WSPR. The primary purpose of beacons is the checking of propagation conditions both for every day amateur use and for special propagation research projects.

Narrowband modes with a maximum bandwidth of 2.7 kHz in common with all VHF, UHF. and microwave band plans are always found at the bottom of individual allocations. This is where you will find Morse (CW), telephony (SSB) and machine generated mode (MGM) activity such as PSK31 and JT6M Most CW and SSB activity will be conducted around 70.200MHz but you must be aware of the specific band allocations of other European countries as these often differ from the UK allocation.

70.250-70.294MHZ    ALL MODES
This non-channelised area of the band is allocated to any mode with a maximum bandwidth of 12 kHz.
The 70MHz band is unique insofar that it has an AM.calling frequency on 70.260MHz.

70.375   Local chat frequency in the Reruth area

70.2625 –  EI FM Calling channel
70.450   – UK FM Calling channel

This section of the 70MHz band is allocated to all modes channelised operation where both telephony and digital modes exist. These are narrowband FM (NBFM) channels with 12.5 kHz spacing and in this sub-band area you’ll find FM telephony, packet radio, RTTY and internet gateways.

Incidentally although the UK and Ireland usage column of this sub-band indicates that the majority of channels are used by digital modes, internet gateways or emergency communication groups that does NOT mean you cannot use them for FM telephony. It is simply a case of listening on these channels to ascertain LOCALLY whether they are in use or not. If you hear no other traffic then you may conduct your contact on any channel you wish to use.

There are now a number of countries within IARU Region-1 that have permanent access to the 70MHz band. However not all countries possess the 500kHz of bandwidth that we have in the UK and individual band (and band plans) can be exceedingly fragmented.

Many countries with permanent and temporary 70MHz allocations are located at an ideal distance from the UK for a number of propagation modes that includes aurora, meteor scatter and Sporadic-E. Numerous stations are now active on the 70MHz band and some of them operate on FM as well as CW and SSB and therefore can be worked on converted private mobile radio (PMR) sets.

For some years stations in South Africa (ZS) have had a 70MHz allocation. The 9000km path between the UK and South Africa is particularly interesting as both ends lie at the extremity of the trans-equatorial zones. A contact over this TEP path is quite possible around Sun Spot maximum and should take place when conditions are particularly good on the 50MHz band. Possible openings between the UK and South Africa will probably occur during the month of October.

Thursday, 15 May 2014

70 Mhz 5/8 wave Ring Base antenna.

Recently my Sirio CX-4-68 70 Mhz antenna got damaged and needed to be taken down and fixed or replaced. I have used the Sirio for a few years now with great results, so I decided while I was getting around to fixing it I would try out a different antenna. I picked the Sirio Ring Base antenna from Sandpiper, this is a 5/8 wave antenna with a ring on the bottom.
Being a 5/8 wave it should have similar gain: Gain on Sirio CX-4-60 is rated at 4.15 dBi and on the Sirio Ring Base is 5.1 dBi so there is very little between them.
Now for the new antenna.....
As I said it it is a 5/8 wave antenna with the radiating element (above the ring) is 2.54cm , the CX-4-68 has a radiating element of 210cm.
The construction of the Ring Base is very simple, you have the base part where the brackets for the pole and the ring part goes as well as the SO239 socket is.
The next are 2 aluminum tubes which slot into the base piece.
There is a chart for the over all measurements of the sections in order to give minimum SWR, once the instructions are followed there will be no problem.
As regards to on air testing, I only have the antenna up since last Sunday, so testing is a minimum..
Having said that I did do a test with Jim EI2HJB/M outside his house in Blackrock, County Louth and the signal was very good both ways, then to Ben EI4IN in Skerries County Dublin, he told me that my signal was much improved, I then done a test with EI2KC/M heading out to Collon County Meath and again signals both way was very strong.
It is hard to judge it so far, but I can't say if the ring base is better as the CX-4-68, it does seem to be very similar, I need to get the CX-4-68 back up and at the same height to tell if there is any difference, both appear to be excellent antennas.

Friday, 9 May 2014

What am I up to?????

Simoco PRM8040.

Sorry I have not updated my Blog in the last while, I have been under the weather a bit!!
I have however ordered my new Ring Base antenna for 4m and also got delivery of a Simoco PRM 8040 which I will reprogram for 70Mhz.
As soon as the antenna arrives it will be put up and I will post here on how I get on with it.
Also down in the south of Ireland there is a great 4m link, it is on Mount Leinster as far as I know and it connects into the South Eastern Repeater network, which consists of 2m and 70cms repeaters scattered all over the South of Ireland.
The link operates on 70.400 with a CTCSS of 67.0 Hz, have a listen and try it out.

Saturday, 29 March 2014

Sirio CX 4-68 down for repairs.

I came home from work the other day and while having a coffee looked out the kitchen window and seen a length of aluminium tubing leaning against the wall, I thought to myself that my neighbour had come across the aluminium and dropped it in for me to use as an antenna, not the first time he has done this!!
When I went out to have a look at it I realised that it was from my 4m Sirio CX 4-68 antenna and that aluminium was from the vertical radiating section.
The antenna broke where the vertical section screws on to the top of the loading coil, the “sleeve” which holds the vertical rod in place has shattered and split.

I took the antenna down today and replaced it with a 4m dipole for the time being, I will ask one of my friends to weld a tube of brass or something on to the threaded piece and slot it so that I can put the radiating section back on, then I will be back using a decent antenna again!!!
Antenna showing location of damage.

Damage to where the radiating element joins to loading coil.

The damaged section will need to be removed and a new "sleeve" added so that vertical piece can be joined back on.

Sunday, 9 March 2014

Handheld radios, do I need more????

As promised a photo of all my Handheld Radios, I think this is all of them!!! Well it is all I could find in my shack…… A man can never have too many handheld radios, in my opinion!!!!!
To be honest, I only use one of them regularly and that is the Kenwood TH-F7 as this has a 4 amp battery on it!! The small Shouao was bought from eBay for very little money, the Wouxun KG-UVD1P is 4m and 2m so I only use that when I need to go /P on those bands, the TYT TH-UVF8D (Yellow Radio) is in a grab case with spare battery, battery case etc for emergency in the boot of my car. and the rest are kept in storage in case they are needed for AREN. 

Top Row, left to right: Shouao 2m, Kenwood TH-F7 2m & 70cms (HF & 6m RX), TYT TH-UVF8D 2m & 70cms, Wouxun KG-UVD1P 4m & 2m, Icom IC-2AT 2m, 2 x Radioshack 70cms.
Midle Row: 7 x Motorola GP-360’s for 2m (AREN Use).
Bottom Row: Selection of 446 Mhz radios, handy for handing out to “Non Hams”.

Sunday, 2 March 2014

New shack layout.

I recently updated some of my equipment in my shack, I am now back on HF, but do not get excited, I am not a DX'er or Contester. I do like listening and doing a bit of rag-chewing on the lower bands, and of course on the 4m band as well....

Top Row, Left to Right: Yaesu FT-857D (HF,6m,2m,70cms) with LDG FTL-Meter on it's left, Yaesu 2900R 2m FM (75w), Simoco PRM-8020 on 4m FM,Anytone AT-5189 4m FM, Kenwood TK-7180 2m FM, CRT 2M-1 2m FM.

Bottom Row, Left to Right: Wouxun KG-UV920R 2m & 70cm FM,Cleartone CM-7200 4m AM & FM, Simoco SRM-9020 70cm FM.

In the background on the shelf (again left to right) Motorola GP-360 on 2m FM, a very old Icom IC-2AT 2m FM and a TYT TH-UVF8D on 2m and 70cms.

I will post a photo of all my handheld radios later... and I mean "ALL".......

Saturday, 22 February 2014

Phil ON4TA portable on 4m SOTA in Ireland.

Here is an email I received fro Phil ON4TA from Geerbets in Belgium.
Please keep an ear out for him on 4m when he is working SOTA in our area.

Hello Tony,

Just to advise that I plan to be in Ireland on a two weeks holiday at the end of March.  It will be my first visit to the North East, weather permitting I will be out and about on SOTA in the Cooley Peninsula and the Mourne Mountains.

I was browsing your website and see that you are on 70.400MHz so for sure will try that frequency.  EI7GEB Dave suggested dropping you a line as I will be looking for VHF contacts from the hill tops.

There seem to be pockets of 4m activity in Ireland.  On a previous visit I worked the folks in Co. Galway and Co. Mayo from many of the Connemara hill tops.  I met up with Artur EI7GMB and Steve EI5DD, they are very much into Clansman equipment too (I enjoyed the photo’s on your website).

I usually work VHF from the hill tops with a handheld and SlimJim antenna on 4m, 2m and 70cm.

Looking forward working you and other 4m enthusiasts in the Drogheda area.

Best 73, Phil ON4TA

Wednesday, 1 January 2014

Some interesting 4m antenna projects.

Looking around the interned today I came across a few quite interesting home brew antennas for the 70 Mhz band.

1The Hentenna:

 2. Vertical half-wave aerials for 4m:

3. A centre-fed "co-axial" dipole for 4m:

4. 7 Element 4M (70MHz) Beam By Paul Graver M1CCZ:

Tuesday, 24 December 2013

A very merry Christmas to all my readers and followers.

Christmas is upon us once again and 2013 is coming to an end. I would like to thank all those who stopped by by and had a look at my Blog over the last 12 months.
Sometimes it can be difficult to come up with something to write about but with meeting people like Artur EI7GMB who introduced me to the world of Cleartone Radios and Clansman equipment I have had plenty to write about, not to mention that my shack is now full to bursting point!!!!!
I hope that 2014 will have plenty of 70Mhz surprises in store for me, and of course I will share them here for you to read.
So Hopefully coming in 2014: (My wish list)
A better 4m antenna at my QTH.
See if I can go portable on 70Mhz from hilltops with one of the Clansman 352's.
Seek out and get my hands on more exciting 4m radios.........
And of course try to use the band a little more myself, I have been a bit busy with work in 2013 (which is not a bad complaint) More money for radios... LOL....

Have a very Merry Christmas and a Happy New Year...

Sunday, 24 November 2013

2 more additions to my Clansman collection, one a surprise!!

I recently bought a 12-14V DC charger for my Clansman, I already have the bigger ones that can be either plugged into the mains or 12V DC, those ones will charge 2 batteries at a time and can work as a power supply to run one of the Clansman's.
These are great but a bit too bulky for mobile use.

Clansman 2 battery charger/power supply.

12-14V DC Rapid Charger.

The latest battery charger only works from 12-14V DC and can only charge one battery at a time, the reason I bought this is that I can charge the battery from the cigar plug in the car. The Clansman Fast Battery Charger (D.C. 14V, NSN 6130-99-620-2114) charges 24 volt batteries from 12-14 Volt DC input. Features include a shorter charging time, automatic termination of charging when the batteries are fully charged and a fully charged battery indicator. 

Now for the "SURPRISE" that I mentioned in the heading......
When I purchased the Rapid Charger I got chatting to the guy who was selling it, he had a few extra Clansman pieces on eBay and was selling everything as he need the space, I sent him a link to the Blog and he had a little read...
When I picked up the package it seemed a little bigger and heavier than I thought it would be and when I opened it I found the following:

Hand Cranker Charger.
Clansman Hand Generator for use with the Clansman radios PRC-344, PRC-351, PRC-352, PRC-320. 
Clips on between the radio and the battery and by turning the hand crank it generates 24 Volt DC for charging a standard Clansman 24 Volt battery to operate the radio. 
Charge lamp lights up to indicate when the hand crank is being turned at the right speed.
What a surprise that was!!!!!

Hand Cranker/Generator added to one of my Clansman Radios.

Thursday, 21 November 2013

Another Clansman Antenna Idea for 4m!!

It is a cold day out today and I needed something to occupy my mind, I was thinking about the antennas that I already have for the Clansman.
The one I made up to use with the amplifier works very well and the original 2, the Telescopic Whip and the Battlefield antenna are a bit of a compromise.
I decided that what I need is a pre-tuned flexible antenna that will connect into the Clansman antenna socket so that I can change from one antenna to another quickly.

Quick release antenna base on SURF.

I asked Pat (EI2HX) what whips he had that would suit 4m, he brought over a few and with a bit of negotiations and a lot of tea I picked a few antenna whips,  one similar to the one I use on my car with a base loading coil would be called into service.

Bottom of black steel whip antenna.

This base has a 6mm thread so I would need something to use as an adaptor that will fit onto the Clansman antenna base, with a quick look on eBay I spotted spare bases for the bottom of the Battlefield Antennas, so I bought 2 of them.

Base showing 6mm thread.

One of the connectors bought on eBay.

The Battlefield antenna base has an 8mm thread so a bit of work needed to be done….So out came the files and Die Set.

Collection of files.
Different Die sizes.
Firstly I filed off the existing 8mm threads from the antenna base, then used a 7mm Die, when the new 7mm threads were done I then filed them off as well…. Then the 6mm Die was used, with the new 6mm threads done the Battlefield Antenna base screwed up nicely to the new 4m whip antenna.

Antenna with new fitting added.

The antenna is approx. 32 Inches long and very flexible, being black it suits the Clansman very well, on air testing with locals has showed that it is an improvement over the telescopic and battlefield antennas.

New antenna fitted on radio via SURF.

This antenna I made up primarily to be used on the radio with or without the SURF and on the 4w power.

Sunday, 3 November 2013

Clansman "Loudspeaker"

Recently I got my hands on a Clansman extension speaker for my Clansman 351, it is a very heavy duty speaker made to take the most abuse that can be thrown at it.

Front of speaker with 7 pin plug.

It came with a short lead with a 7 pin plug on each side.There is a socket on one side with a pair of connectors so that the speaker can be connected to the radio with twin speaker cable, there is a volume control on the top.

Top of speaker, volume control.
The speaker can be directly connected to the radio with the short 7 pin lead that came with it, the handset/headset can be then connected to the speaker.

Side view with connections.
This would be a great way to operate the radio/speaker/handset but with only one “small” issue… one I overlooked when buying the speaker was the fact that the Clansman radio does not have any audio amplification circuitry built into it so I will need to buy an external audio amplifier or build one (thinking of using the audio circuit from old computer extension speakers).

Audio amplifier.
The reason why I got the speaker was so that I can set up portable and have lots of sound rather than using an earpiece.
When I buy the Clansman audio amplifier I will use it in the shack as they run from either 12v or 24v and this would be too much to bring with me.
The audio amp I plan to build will work off either 6 x 1.5v AA or a 9v PP3 battery enclosed in a waterproof small box “Velcro” to the back of the speaker.

Back of speaker.

Monday, 21 October 2013

Disabling the 150Hz tone from the Clansman PCR-351/2 by Andrew EI3FEB.

The Clansman PRC-351 is a military VHF Man pack set that was manufactured for the British Army in the late 1970s. It is fully synthesized and covers 30 - 76MHz in 25KHz steps, making it suitable for the Amateur 6 and 4 meter bands. Power output is 4 watts of FM, however an optional 20W clip on module is also available.

With the British Army's move to the newer Bowman series of radios, many older Clansman Series are becoming available on the surplus market at reasonable prices. The basic unit is available for less than 50 Euro although a further expenditure of 20 Euro for a 24v/1AH battery and 15 Euro on a Clansman headset would be required.As this radio has a BNC socket in addition to its 1.2m whip antenna, it was possible to connect it to an external 4m half wave antenna enabling contacts with Michael EI3GYB and Arthur EI7GMB covering distances of 40 Km and 15 Km respectively. Due to the set's 25KHz channel spacing the 4m it does not cover the calling frequency of 70.2625. Contacts were scheduled via another 4 meter set before QSYing to a channel available on the PRC-351.

There was a notable presence of a 150Hz  tone superimposed on the transmitted audio. This is due to the military tone squelch used by US and UK military radios. A Google search led to the PRC-351 Yahoo Group which had instructions on how to disable the tone squelch.

Disconnect the antenna, accessories, and battery. 
The battery is held by the spring clips seen on the bottom of the set.

Open the 4 Allen Bolts on the side of the set containing the audio sockets.

Carefully remove the end panel of the radio.
It is connected to the main radio body by a fragile ribbon.

Remove the connector joining the end panel to the radio.

Remove the 4 Allen Bolts on the control panel and slide the radio out of its housing.
     Locate R9 on Module 13 - this is the preset resistor that adjusts the level of the 150Hz tone.

Rotate R9 fully anti-clockwise

Re-assemble the set taking care not to tear the sachets containing desiccant which prevents condensation inside the set.

Subsequent QSOs confirmed that this modification had disabled the 150Hz tone. On air tests revealed that this set had a sensitive receiver and the FM audio quality was comparable if not equal to other PMR sets tested.

A back pack frame is available to carry all of the components of the set whilst it is fully operational. It is possible to acquire a canvass ruck-sack which performs a similar function. The canvass ruck-sack along with a trailing wire antenna was designed to disguise the radio thereby making the operator less of a target in the field.

Special thanks to Andrew EI3FEB for his work on this transceiver.