[Collins] 32S1 crystals

[Gerald]

On Tue, 2005-09-20 at 17:15 -0400, Craig Roberts wrote:
> Well, Glen's right -- you can "piggyback" your receiver's crystals if 
> you hook up the 32S-1 and 75S-1 in transceive mode and switch your 
> transmitter to the Receiver VFO setting (please see the manual for 
> precise instructions.

Not quite correct.

When you connect the 32S and 75S for transceive, you use the receiver
crystals for transmit, whether in transceive or separate modes. So you
CAN work split within one 200 kHz segment. Most often useful for CW
split though if you had a 14.1 MHz crystal you could probably work
useful SSB split on 20m. The transceive / independent switch does not
change the crystal source, only the PTO source. Especially in transceive
mode, errors in BFO and carrier crystals can lead to errors between
receiver and transmit frequencies.

To have transmitter and receiver completely independent, you need
crystals in both and to disconnect the cable between the crystal
oscillators, replacing the cable with a load in the receiver and with
the cable from the crystal oscillator in the transmitter.

>  As Glen says, the manuals can be downloaded for 
> free from the www.collinsradio.com site).  If you don't have a set of 
> interconnecting cables, you can make them up or, better yet, buy a set 
> from Glen himself.-- if he still sells them. 
> (http://home.comcast.net/~zcomco/new_price_list.htm) . Historically, 
> there's been a lot of discussion about proper cable length and the type 
> of coax cable to use -- and even the RCA plugs to terminate them.  
> Buying a ready-made set avoids controversy :-) .
> 
> Without the crystals, you can't use your transmitter independently 
> (which is essential for split frequency operation and desireable for 
> CW).  Sets of crystals for the S-Line are sometimes available on eBay, 
> though the condition of them is always a mystery.  A really good source 
> of new Collins crystals, seldom mentioned, is MH Electronics at 
> www.mhelectronics.com.  Their prices are better than International's and 
> they are very knowledgeable about Collins gear. Call them with your 
> requirements and you'll get very friendly service.
> 
> To save money, you might wish to purchase crystal only for the bands 
> you'll be using.
> 
> 73,
> 
> Craig
> W3CRR

Burghardt, 
(http://www.burghardt-amateur.com/Burghardt/HTML/main_frame.html) in SD
has some Collins crystals but none for common ham band frequencies. Many
on their list are not for standard S-line frequencies.

Below 12 MHz or so, the crystal frequency is 3.155 MHz above the bottom
edge of the segment covered. Its most convenient if the segment begins
with x.000, x.200, x.400, x.600, or x.800 KHz, but any crystal that will
fit the socket will work. Above 12 MHz or so, the crystal frequency is
1/2 of the frequency 3.155 MHz above the bottom edge of the segment
covered. So for the lower bands standard crystals all have frequencies
ending in .x55 KHz. For the higher bands crystals end in x.y775 for even
100 KHz band edges, but for odd 100 KHz band edges they end in x.y275.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer