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Old May 17th 07, 10:35 PM posted to rec.radio.amateur.boatanchors
RapidRonnie RapidRonnie is offline
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First recorded activity by RadioBanter: Jan 2007
Posts: 18
Default Ham bands only rigs, off-band operation?

On May 16, 9:37 am, (Scott Dorsey) wrote:
Rick (W-A-one-R-K-T) wrote:

Typically, can ham-bands-only receivers such as the Drake R4 and Collins
75A or 75S series, transmitters such as the Collins 32S and Drake T4
series, and transceivers such as Drake TR-4 and Collins KWM-2, be modified
to work on CAP and MARS frequencies?


The KWM-2 was designed as a wideband radio and can cover most of the HF
bands. They were sold to many government agencies and the ham market was
a small part of the total sales. The ham models are only lacking the
full crystal board to be used across the band.


As I said:

Collins S-Line (which includes KWM-2) is not strictly "ham band only"
in the normal sense of the word. There are 15 or 30 selectable crystal
positions which give a 200 kHz swing in the ranges of 3.4-5.0 and
6.5-30.0 MHz.

In other words, you do not have all the HF ham allocations, because
you have no 160 meters. You also do not have the new 60 meter
allocations, specific 5332-5405 channels.

S-Line gear made with the single crystal deck may be upgraded to the
dual deck configuration. You still only get 30, 200 kHz snippets.
That's a total of 6000 kHz or 6 MHz total coverage. The 32S-x
transmitter and KWM may be run with an external mixing source, such as
a signal generator or VFO. The receivers can also with some minor
mods. This is not my definition of "general coverage".

Additionally, you do not have true CW transmit except on the later
S-3 transmitter, and you do not have AM transmit on the KWM-2 or the
32S unless modified. Even then, it's not full plate modulation.

S-Line Collins is (as Bret puts it) "JFK/MM era stylish" and
reasonably well built but is not a mil-spec box.

I'm not at all familiar with Drake but I know they are well liked and
apparently in modified form are the choice of hardcore contesters,
over Collins or true comm/mil gear.