Calling all GEC Outfit CJA & CJC owners. - UK Vintage Radio Repair and Restoration Discussion Forum

Don Collie jnr · 15th Sep 2010, 8:46 am

I am the proud owner of one of these receivers [plus synthesiser - 77 valves total, 33 in the receiver], and am in contact with two other owners of same.
If you have one, we would like to hear from you. I might even set up a group
to share information, technical problems, etc.

Please PM me if interested.

Don.

G8HQP Dave · 15th Sep 2010, 12:08 pm

Unfortunately I have no information to offer, but I do remember Pat Hawker referring to this receiver in his Technical Topics in RadCom many years ago. He was talking about high dynamic range front-ends, and mentioned the ECC82 used for a cascode RF amp and balanced mixer. He gave just enough information to excite interest, but not enough to satisfy it!

Don Collie jnr · 16th Sep 2010, 3:23 am

Hi Dave,
Yes, I`m fond of my CJA. Nobody ever regretted buying [$150] quality, OR : It`s not worth restoring something that never worked well when new. The CJA overload relays trip at 2.7V rms at the antenna input, and there are 6 tuned circuits and two ECC82 [CV4122] cascode amplifiers before the mixer. SNR is
0.5uV for 16dB. It drifts 10 KHz on warmup, and then is stable. Using the synthesiser, it can be locked to the nearest 100Hz, with the accuracy and stability of the reference oscillator used. It`s a valve behemoth which weighs 150 Lbs, but fun to use and work on. I use it on the local AM net on Fridays at 8-00pm. There are 74 adjustments on the turret, not including those on the dual IF`s, and dual demodulators.

15th Sep 2010, 8:46 am	#1
Don Collie jnr Retired Dormant Member Join Date: Jul 2008 Location: Invercargill, New Zealand Posts: 51	Calling all GEC Outfit CJA & CJC owners. I am the proud owner of one of these receivers [plus synthesiser - 77 valves total, 33 in the receiver], and am in contact with two other owners of same. If you have one, we would like to hear from you. I might even set up a group to share information, technical problems, etc. Please PM me if interested. Don. Last edited by Darren-UK; 15th Sep 2010 at 11:26 am. Reason: Sticking full-stop key problem fixed.

15th Sep 2010, 12:08 pm	#2
G8HQP Dave Rest in Peace Join Date: Sep 2008 Location: Solihull, West Midlands, UK. Posts: 4,872	Re: Calling all GEC Outfit CJA & CJC owners. Unfortunately I have no information to offer, but I do remember Pat Hawker referring to this receiver in his Technical Topics in RadCom many years ago. He was talking about high dynamic range front-ends, and mentioned the ECC82 used for a cascode RF amp and balanced mixer. He gave just enough information to excite interest, but not enough to satisfy it!

16th Sep 2010, 3:23 am	#3
Don Collie jnr Retired Dormant Member Join Date: Jul 2008 Location: Invercargill, New Zealand Posts: 51	Re: Calling all GEC Outfit CJA & CJC owners. Hi Dave, Yes, I`m fond of my CJA. Nobody ever regretted buying [$150] quality, OR : It`s not worth restoring something that never worked well when new. The CJA overload relays trip at 2.7V rms at the antenna input, and there are 6 tuned circuits and two ECC82 [CV4122] cascode amplifiers before the mixer. SNR is 0.5uV for 16dB. It drifts 10 KHz on warmup, and then is stable. Using the synthesiser, it can be locked to the nearest 100Hz, with the accuracy and stability of the reference oscillator used. It`s a valve behemoth which weighs 150 Lbs, but fun to use and work on. I use it on the local AM net on Fridays at 8-00pm. There are 74 adjustments on the turret, not including those on the dual IF`s, and dual demodulators.