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Old November 17th 07, 05:17 PM posted to rec.radio.amateur.boatanchors
J. Heijboer J. Heijboer is offline
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First recorded activity by RadioBanter: Nov 2007
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Default Racal MA161 Receiver Fine Tuning Unit

The MA-161 belonges as far as I know to the range of RA-17 and/or RA-117
receivers. I own one myself (serial number N1) but also do not know much
about the unit. Unfortunately also no documentation available....

Cheers,
Johan (PE1RHC)

"Chris Suslowicz" schreef in bericht
...
In article
.,
Antonio Iovane wrote:

On 16 Nov, 22:09, (Chris Suslowicz) wrote:
In article
.,

Antonio Iovane wrote:


...but I think it isn't what you think it is. I guess it
should belong to the family of external local oscillators that were
used in substitution of internal LO. It is tunable within +/- 500 Hz
with marks every 10 Hz. It has only one output connector and no input
whatsoever.

Ah. In that case it's an add-on feature to make a 1kHz resolution
synthesized receiver into a free-tuning one.

Basicly what I would like to know is what receiver it was
meant for

No idea, except that it will *not* have been anything cheap, and
possibly not a commercial item. Maybe Naval or long-haul short wave
communication links? COMCAN? Expect something huge and rackmounted.

what of the local oscillators it would substitute, and
whether anybody have any reference to point me to.

Google fails to find anything, unfortunately.

Chris.


Not so huge, rack mounted but only two rack units, four valves, a
small crystal oven with two crystals, a tuning knob with dial, a
rotary switch which says: NORMAL, NORMAL +/- dF, FSK, FSK +/- dF.
My unit has serial number N00016. Probably only very few units were
ever made. No track anywhere. Probably this unit of mine is the sole
survivor today.


The complete installation *will* have been huge - probably a rack full -
as that's almost certainly off something like the COMCAN long-haul
teleprinter network.

Unfortunately, it's too recent to appear in Wireless for the Warrior,
but I'd expect the complete installatiopn to consist of two receivers
with diversity switching, "Racalator" or similar synthesized tuning
to 1 kHz resolution followed by the MA161 to take it down to 10 Hz,
ISB and FSK adaptors, and possibly the "front end protection unit"
if there were high powered transmitters at the same site.

Another possibility is that it's part of something like the RTA-191
which was a modular receiver that filled a 6-foot rack...

You need someone with experience of COMCAN or the Defence Teleprinter
Network, I suspect.

Best,
Chris.
Chris.

--
What happened to the testers of Preparation A through G?