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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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7th Aug 2022, 3:20 pm | #21 | |
Triode
Join Date: Oct 2005
Location: Southampton, Hampshire, UK.
Posts: 46
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Re: South Midlands Communications SMC-73 RX
[QUOTE=David G4EBT;1489253]
Quote:
"FET's are employed in the R.F. Amplifier, mixer, VFO and BFO (these latter two stages being fed from independent stabilised supplies) ensuring good sensitivity, stability (electrical and mechanical) dynamic range (helped by adjustable RF attenuator), and marked freedom from "pulling" of both the local and beat frequency oscillators". Cosmetically it's so similar to the 9R59 that it certainly looks like it has Trio's fingerprints all over it, but branded 'SMC'. SMC were quite an outfit in the 70s. They still exist but have abandoned amateur radio (I don't know when) and reverted back to what they did at the outset - antenna masts and professional communications. Not been located in the South Midlands for many years. Whether they still have any staff or records relating to their amateur radio years who could perhaps throw any light on the 'SMC 73' radio I very much doubt after 44 years, but it might be worth a try: https://www.devex.com/organizations/...ions-ltd-38487 Link is well out of date, I retired 8 years ago, there is no amateur radio information available as it was all scanned and then sold/removed in 2002 so no point in wasting time asking anybody at SMC or people emaiing me for help as the link gives my name. Geoff Brown G4ICD
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Observation is 90% of the repair Last edited by Geoff G4ICD; 7th Aug 2022 at 3:37 pm. |
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7th Aug 2022, 9:00 pm | #22 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,015
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Re: South Midlands Communications SMC-73 RX
That's very interesting Geoff.
I well recall the Chandlers Ford address but not an Axminster one. I visit Axminster now and again - a very nice place. I don't suppose you have any info about this old RX? We would love to know details about a solid state version of the 9R59. <Later edit> I was out of sync here. Mods please delete if appropriate. My sentiments remain - looking for a schematic if anyone can oblige please. |
16th Aug 2022, 8:04 pm | #23 |
Hexode
Join Date: Mar 2009
Location: Minneapolis, Minnesota, USA.
Posts: 279
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Re: South Midlands Communications SMC-73 RX
This thread ran in parallel with another with the same subject at the RSGBWorkshop group at groups.io
There, Martin, G8JNJ, noted that the SMC-R73 was the same as the Minix MR-73B. See https://www.rigpix.com/minix/minix_mr73b.htm Ian, M5IJH, found a translated copy of the German manual for the Minix MR-73B. I have attached it. It should be enough to keep most of us happy. It was also noted that the MR-73B looked like a forerunner of the DX200/qp666 and clones. HTH and 73 John KC0G / M0KCY Last edited by John KC0G; 16th Aug 2022 at 8:06 pm. Reason: typo |
17th Aug 2022, 8:28 am | #24 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,015
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Re: South Midlands Communications SMC-73 RX
That's excellent John - thank you very much. A nice touch it includes a 3.5MHz marker to find the edges of the ham bands.
So ordinary JFETs 2SK19 in RF MIX and LO... |