[R-390] CV 157 stuff

[John Vendely]

Sheldon,

That's very interesting.  I used to listen regularly to these ISB 
feeders, using a R-390A/CV-157, or a R-390A/TMC SBC-9/AFC-2, which was 
TMC's answer to the CV-157.  Phase locked to VOA's pilot carrier as 
intended, you got great broadcast quality SSB.  I recall during the 1976 
presidential elections hearing VOA election coverage in English on USB 
and the same coverage in Russian on LSB.  BBC and Radio Moscow also used 
HF broadcast feeders in those days, though without the pilot carrier.  I 
think the VOA ISB feeders disappeared around 1994 or so.  Pilot carrier 
AFC is relatively rare today, but still exists on some ISB data 
transmissions, e.g. NATO Link 11.

Man, I sure would like to add one of those huge RCA SSB-R3A receivers to 
the collection.  If anyone knows of one for sale, please let me know.

p.s., I have a TMC MMX-2 exciter which was surplussed out of the now 
defunct VOA Bethany Relay station, where it was used in one of the ISB 
feeder transmitters.  It lives on in my shack, in a TMC 1kW transmitter 
which I have on the air regularly...

73,

John K9WT


On 2/21/2014 4:33 AM, Sheldon Daitch wrote:
> Voice of America used ISB transmisions for many years for program feeder service prior to going to satellite circuits for all programs.
>
> There were four ISB transmitters at the Greenville NC VOA complex (TMC GPT-10s converted to TMC GPT-40s) and then two Continental ISB transmitters were added.
>
> Delano had two ISB transmitters, but if memory serves me correctly, the two Continental ISB transmitters added were removed from Delano.
>
> The numerous receiver sites overseas used, in the latter years, RCA SSB-3 ISB diversity receivers. VOA must have had about a hundred of these receivers and typical operation was one program feed on USB, another program feed was on LSB.  The RCA receivers were the later mixed tube-transistorized systems, versions of the fully tubed unit RCA was marketing in the mid-1950s.
>
> Greenville Receiver site had 8 of the RCA receivers for program feeds to Washington, but we also have two older ISB diversity systems, using Racal RA-17 receivers and Pioneer ISB demodulator/diversity combiner systems.
>
> 73
> Sheldon
> WA4MZZ
>
>
> ________________________________________
> From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> on behalf of rbethman <rbethman at comcast.net>
> Sent: Friday, February 21, 2014 1:16 AM
> To: r-390 at mailman.qth.net
> Subject: Re: [R-390] CV 157 stuff
>
> The USAF used to use Independent SSB transmissions.
>
> This was typical of SAC operations.
>
> This may be what they used these for.
>
> Bob - N0DGN
>
>
> O
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