"RapidRonnie" wrote in message
ps.com...
On May 7, 9:13 pm, (Michael Black) wrote:
"Rick " ) writes:
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?

I know that some radios have provisions for installing crystals so that
they'll work on off-band frequencies.

How can I determine which radios are modifiable that way, and also
where
is a good place to get crystals these days?

CAP and MARS frequencies were (I don't know if it's the case now)
generally
chosen to be adjacent to ham bands so ham equipment could be used.
There's
little sense of having an auxiliary if the operators have to buy
extra equipment or the organization has to do so.

Remember, they date from before the new fangled equipment came along.
Transmitters were easy, just pop in a suitable crystal and the rest of
the unit would have enough leeway to tune the adjacent frequency.
Receivers
were more of a problem, since retuning generally meant retuning the
local oscillator, there weren't always crystals to select the range. But
a receiver that had a bit of overlap was usually okay.

Hence, most equipment would be modifiable, if there wasn't enough
overlap.

Michael VE2BVW

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.

It's possible to use an external frequency reference to hit a "dead
nuts on" transmit frequency but for normal use you only have to be
within a designated band limit. There was a crystal accessory
originally intended for Novice ham use when they were rockbound.

Use a counter or service monitor to check your transmit frequency if
you are worried, but I doubt MARS or CAP is going to care if you are
1 khz or less off. Come to think of it, what are CAP's HF allocaions
anyway?

CAP members, like MARs, are instructed not to reveal any frequency
allocations due to OPSEC.


J

On May 8, 11:26 pm, "Jerry" wrote:
"RapidRonnie" wrote in message

ps.com...





On May 7, 9:13 pm, (Michael Black) wrote:
"Rick " ) writes:
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?

I know that some radios have provisions for installing crystals so that
they'll work on off-band frequencies.

How can I determine which radios are modifiable that way, and also
where
is a good place to get crystals these days?

CAP and MARS frequencies were (I don't know if it's the case now)
generally
chosen to be adjacent to ham bands so ham equipment could be used.
There's
little sense of having an auxiliary if the operators have to buy
extra equipment or the organization has to do so.

Remember, they date from before the new fangled equipment came along.
Transmitters were easy, just pop in a suitable crystal and the rest of
the unit would have enough leeway to tune the adjacent frequency.
Receivers
were more of a problem, since retuning generally meant retuning the
local oscillator, there weren't always crystals to select the range. But
a receiver that had a bit of overlap was usually okay.

Hence, most equipment would be modifiable, if there wasn't enough
overlap.

Michael VE2BVW

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.

It's possible to use an external frequency reference to hit a "dead
nuts on" transmit frequency but for normal use you only have to be
within a designated band limit. There was a crystal accessory
originally intended for Novice ham use when they were rockbound.

Use a counter or service monitor to check your transmit frequency if
you are worried, but I doubt MARS or CAP is going to care if you are
1 khz or less off. Come to think of it, what are CAP's HF allocaions
anyway?

You are full of ****!!!!!!

CAP is civil search and rescue. MARS is military AFFILIATE-not
operational.

Full of ****. Just for that I'll monitor and post a couple.

There were external VFOs that provided all the possible frequencies
for both the xtal osc and the VFO. A Jaapanese company made one. I
think a service monitor will do as well if the output level is high
enough, most have programmable frequencies like scanners. I think if
the weight and size weren't prohibitive the IFR 1500 would be ideal
because it's available cheap and because it has full duplex unlike the
more common 1200/500 series. You could of course just use a sig gen,
again, assuming the level is high enough. No where in the Collins
manuals is the drive level needed specified!


Most hams are such cheap asses the idea they should have a service
monitor would them **** their pants. Then again, most hams are so old
they do that anyway.

I just checked the compliant CAP list of commercial HF gear. Neither
Collins, Drake, Icom, Ten-Tec or Kenwood had any amateur equipment that were
on the compliant list. The only ham rig I could find that was on the
complaint list was a special version of the 817, and then it had to be
operated under 5 watts and it was not compliant on vhf.

The use of a compliant list means that if you are using a non-compliant unit
and use elaborate equipment to monitor the frequency to the nerest tenth of
a Hz, you are still non-compliant. In short, there is nothing you can do to
make it compliant.

It is similar on Search and Rescue frequencies. Althoughamateur vhf
equipment can be modified to operate on Search and Rescue, it is not type
certified and therefore illegal. In our state, it is the local sheriff who
holds the license - so any violation reflects upon the sheriff. We do not
allow our local SAR members to operate modified ham gear on the SAR
frequencies.

Colin K7FM

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.

I believe the TR-4 was also originally intended to cover the full HF bands
and the ham version is only lacking some minor options.

How can I determine which radios are modifiable that way, and also where
is a good place to get crystals these days?

By reading the service manuals. ICM is a good source for crystals and
are fine folks to deal with.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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.