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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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10th Feb 2018, 8:08 pm | #21 | |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Spy Set SSTR-1
Quote:
"SSTR-1 notes from a user: It had a single 6L6 as a tri-tet oscillator/final and had 10 watts power output. However opening the long slender case the 6L6 was mounted horizontally and could be immersed in a jar of motor oil. Then with a better power supply I could turn this into 50 or more watts." Lawrence. Last edited by ms660; 10th Feb 2018 at 8:25 pm. |
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11th Feb 2018, 8:14 am | #22 |
Pentode
Join Date: May 2013
Location: Deal, Kent, UK.
Posts: 139
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Re: Spy Set SSTR-1
The manual states a power output of 8 to 15 watts using a 6L6. A 6F6 or 6V6GT/G can be used with reduced output. The psu supplies 400VDC @ 75 mA or 30 W DC. I've never had a long QSO but there is a lot of heat in the confined space of the box.
I can't see how the valve could be immersed in oil. It is mounted horizontal with other components beside it. Have a look: http://militaryradio.com/spyradio/sst-1-b_inside_1.jpg |
11th Feb 2018, 8:59 am | #23 |
Heptode
Join Date: Jun 2012
Location: Southeast Norfolk, UK.
Posts: 772
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Re: Spy Set SSTR-1
It's not the first time I have heard of liquid-cooling a metal-canned 6L6, but the sytem I read about had a water jacket around the metal can and water was pumped through the jacket. I can't for the life of me recall where I read it but it does have a G9BF flavour to the story, so perhaps it was in SWM, although 50w sounds a bit too QRP for G9BF!
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11th Feb 2018, 3:50 pm | #24 | ||
Dekatron
Join Date: Nov 2006
Location: London, UK.
Posts: 3,496
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Re: Spy Set SSTR-1
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So basically approx 50% efficient, nice! Also, it might help then OP to note that this output is achieved with 150V more on the HT+ than he is currently using, so there’s a good way to proceed. Quote:
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Al |
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15th May 2018, 6:58 pm | #25 |
Triode
Join Date: Dec 2010
Location: Rome, Italy.
Posts: 17
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Re: Spy Set SSTR-1
Done or almost done. Tx again with 6V6 and 300 V plate: Out 2 W but I am assembling a new PSU with 400 V and I will use a metal 6L6. RX 3 metal tubes (6AC7-RF Ampl./6AC7- Reg.Det/6Sj7/AF Ampl.) TRF circuit but I am working on a 4 tubes superet. The set is working very well in TX and RX some problem for Net.
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16th May 2018, 5:40 am | #26 |
Heptode
Join Date: May 2014
Location: Salisbury, Wiltshire, UK.
Posts: 998
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Re: Spy Set SSTR-1
Well the build of this replica is certainly a credit, its excellent. Well done.
And a five watt portable rig...what fun! A most succesful project i think and oh, the lettering is just fine. David |
16th May 2018, 7:50 am | #27 | |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,800
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Re: Spy Set SSTR-1
Quote:
An American spy radio, and the music at the start of the film is by Shostakovitch. Shostakovitch found himself in hot water in the Stalin era when government officials decided his music didn't sound 'soviet enough' Maybe the film maker just wanted to give it a USSR vibe, but I'd like to think he had a sense of humour. David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
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