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!!!!

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

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.

UNDERSTANDING THE 70MHZ BAND PLAN

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.

70.000 – 70.100MHZ    PROPAGATION BEACONS
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.

70.100 – 70.250MHZ    NARROWBAND MODES (CW/SSB/MGM)
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.

70.294-70.475MHZ    ALL MODES (CHANNELISED OPERATIONS – 12.5 KHZ SPACING)
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.

PERMANENT AUTHORISATIONS ON 70MHZ
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.

DX OPPORTUNITIES ON 70MHZ
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.