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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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4th Jul 2022, 2:58 pm | #1 |
Triode
Join Date: Dec 2019
Location: Lanarkshire, Scotland, UK.
Posts: 48
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Marconi TF 995A/3/S
What era would the above sigs gen be from, 50s or 60s?
Just civy usage, military useage or both? thanks m |
5th Jul 2022, 3:12 pm | #2 |
Octode
Join Date: Oct 2007
Location: Exeter, Devon, UK.
Posts: 1,554
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Re: Marconi TF 995A/3/S
Marconi TF995A.
Your picture is of the military version, as it has the extra tough steel case, the power supply mounted underneath the main panel instead of inside and the Plessey mark4 mains connector. I cannot read the CT number. The later TF995B/2 was CT520A. It was both civilian and military useage. I have seen the later civilian TF995B/2 with military mod record stickers. The earliest date I can find is 1960 for the TF995. It was not in the 1957 catalogue. It was still being offered 1969. wme_bill |
6th Jul 2022, 7:15 am | #3 |
Pentode
Join Date: Sep 2019
Location: Perth, Western Australia, Australia.
Posts: 199
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Re: Marconi TF 995A/3/S
It looks a lot like the one we had at Wyndham in the Kimberley region of Western Australia in late 1967.
We had several VHF & UHF bearers we looked after, where the Marconi generator we had was pretty useful, with good stability. We had a couple of HF links, too, where a routine test was to check the receiver sensitivity Unfortunately, the HF range on the gen was obtained by mixing the gen VHF output with a single tube VHF oscillator. The latter was very drifty, hence the derived HF would drift in & out of the Rx passband, making the tests very difficult. As it happens, I only have a vague idea of the generator model number, but the TF995 looks very similar, so is probably from the 1960s or very late'50s. |
6th Jul 2022, 1:00 pm | #4 |
Octode
Join Date: Sep 2017
Location: Bristol, UK.
Posts: 1,654
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Re: Marconi TF 995A/3/S
Somewhere, I think I have service and operation manual for this generator. Let me know if you need it.
Mike Last edited by Boulevardier; 6th Jul 2022 at 1:17 pm. |
6th Jul 2022, 10:56 pm | #5 |
Triode
Join Date: Dec 2019
Location: Lanarkshire, Scotland, UK.
Posts: 48
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Re: Marconi TF 995A/3/S
WME Bill, tis CT402.
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7th Jul 2022, 12:20 am | #6 |
Heptode
Join Date: Jan 2008
Location: Ashhurst, Manawatu, New Zealand
Posts: 570
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Re: Marconi TF 995A/3/S
I used to repair these in the 70's - all the NZ CAA workshops had them - they usually were pretty easy to fix - you'll need a good supply of 6AK5 and 6AK6's. I built up quite a stock of attenuator bits after they had a transmitter fired up them! I bought a 995A/2M from our local auction site for not much and it worked on the low bands but the top two HF bands need a 6AK5 transplant. I had to make the 75/50ohm termination but now it's all good. Mine came with the original manual stamped 'Radio Dept, P&T Dept, Dunedin' dated 1st Oct 1968. Just remember - if you want to use it on Saturday, turn it "on" on Thursday!
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Cheers - Martin ZL2MC |