|
Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
|
Thread Tools |
11th May 2015, 3:03 pm | #1 |
Diode
Join Date: May 2015
Location: Hampshire, UK.
Posts: 2
|
Ultra transmitter receiver (British rail)
I was wondering if anyone had ever come across these, I have a set that are paired back to back and when last tested seemed to work. They were made by a company called Ultra Electronics
Type 3A4 AC3 These particular units were manufactured or badged for British Rail (Southern Region) I picked these up from a radio rally quite some years ago with the intention of converting them to 144mhz, they are three channel crystal controlled. hand held transportable with a whip antenna, and come in a leather carrying case. regards Mark |
11th May 2015, 3:18 pm | #2 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
|
Re: Ultra transmitter receiver (British rail)
If anyone knows, then it's the guy behind the Pye Museum:
http://www.qsl.net/gm8aob/ultra.htm Given the age of them, I see a few issues with conversion: 1] They could well be AM. 2] Lots of 'public sector' kit from that era was split frequency - you may find it does something silly like transmitting on 77MHz and receiving on 96MHz. 3] Unlikely to find 'stock' crystals for it - having them ground (to the necessary loading/spec - if you can find it) is unlikely to be cheap! 4] Batteries. Again not going to be cheap since you'll undoubtedly have to have them built to fit. |
11th May 2015, 5:28 pm | #3 |
Heptode
Join Date: Feb 2008
Location: Great Barr, Sandwell, West Midlands, UK.
Posts: 584
|
Re: Ultra transmitter receiver (British rail)
Wow - that's a blast from the past Mark...! The 3A4 was also used by the local police for radar speed trap comms in the early-to-mid 1970s and came into our workshop for repair from time to time. Those were carried in black canvas bags, rather than leather. If my memory is working they used a round multi-cell battery in a blue plastic sheath. Definately AM, and will probably be a challenge to convert to 2m...
|
11th May 2015, 5:49 pm | #4 |
Diode
Join Date: May 2015
Location: Hampshire, UK.
Posts: 2
|
Re: Ultra transmitter receiver (British rail)
Yup, they came with several very extinct round multi-cell batteries that did not hold any charge and ended up rotting / leaking so were disposed of. I had them powered up from a bench Psu for test and at the time both units appeared to be working.
Soon after I obtained them and knowing they were AM I reached the conclusion that it would be a huge disservice to them to convert to 2 meter amateur band, the conversion would probably have required stripping out the radio and retro fitting it with some form three or four channel hand held. So they have pretty much been left in the condition I obtained them in. They came to my attention when I was going through the lab, and I was wondering what people knew about these. regards mark |
11th May 2015, 7:23 pm | #5 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
|
Re: Ultra transmitter receiver (British rail)
The cylindrical-battery-in-a-blue-sheath was a stack of "DEAC" cells - named after the German company that made them.
Try finding some today...! |