[Collins] WARC XTALS for KWM-2A

Thu Aug 2 07:17:07 EDT 2012

S line crystals go from 6555kHz to 16477.5kHz. Frequency limits for the
SI570 standard CMOS version is 10 to 160 Mhz with other variants going to
1.4 Ghz. Used in a number of SDR radios they are considered more than
adequate and I would imagine them to be quite suitable as a 'rubber'
crystal. Jan, G0BBL, sells a simple kit for around $25 I think, I have one
but forget what I paid now. With a simple Windows application it can be
set to any frequency and an external divider should be simple enough to
build up. A divide by 8 would allow the cheapest CMOS version to be used
and would have the benefit that the already decent performance would be
significantly enhanced, phase noise would drop in line with the division.
Of course the trade off with the Si570 type devices is they are not all
that good at tuning rapidly and remaining clean, but as a 'rubber' crystal
that is somewhat irrelevant. The 570 is an I2C bus device but there are a
couple of I2C to USB interfaces out there

I can see two possible solutions for the S line (or indeed other multi
segment radios, Drake anyone? ) A simple 570 oscillator with divider and
buffer driven by a pc application (Should of course have a nice Windows
style front end with photo realistic Collins band selector knobs for
choosing the frequency, together with multiple instances to drive more
than one device, Tx and Rx). Another would have the whole lot in a box
with an LCD display and selector, suitable software within the controller
could take care of different device IF and multiplier variations.

As a kit along the lines that Tony, KB9YIG, does his softrock receivers
and transceivers it should be possible to put something like this out for
less than $200, maybe nearer $100 for the pc controlled version.

Martin, HS0ZED

On 02/08/12 12:41 PM, "appo2 at juno.com" <appo2 at juno.com> wrote:

>I have never seen any article here,,,,about PLL or DSS for Collins.
>I hope if you bought some and tried it with S-line,,,gives us reports,
>JA1AOR is a well known Collins freak!,,,AOR DDS unit for collins
>S line goes for big money in Epay.Does it worth it?
>JG1XLV shows DDS kit for collins,,,,if he is in this thread,,I d like to
>hear
>from him.Must be way below JA1AOR unit.
>We love collins s line,,,bcz it sounds good,,,,,thats all
>K7FT
>
>
>On Wed, 01 Aug 2012 21:40:14 -0500 "Dr. Gerald N. Johnson"
><geraldj at weather.net> writes:
>> Yes, the easiest one probably is a DDS chip from Silicon Labs.
>> The SI570 is one of those chips. According to an on line article
>> from 
>> K5BCQ its rated for 10 to 160 but his does about 3 to 250 Mhz in 1
>> Hz 
>> steps. Its been used with SDR like the Soft Rock and with coarser
>> programming in the controller chip could easily do a Collins local
>> oscillator. It might have more phase noise though which could be an
>> 
>> impediment in a strong signal environment like Europe on 40 meters.
>> The 
>> file I have on my other computer is titled "SI 570 kit from
>> K5BCQ.pdf". 
>> He claims pretty good phase noise. Also I have saved a web page,
>> "Si570_Kit_from_K5BCQ.htm" He uses a simple shaft encoder and with
>> pushes on the encoder (a button) allows selecting the digit to be
>> changed and then changing only that digit so moving in 100kHz or 1
>> MHz 
>> steps after setting in the 3.155 MHz offset would be fairly straight
>> 
>> foward. No doubt a minor amount of software changes in the
>> controller 
>> chip could allow the display to be direct reading in S-line lower
>> side 
>> frequency range with maybe standard 50 or 100 kHz steps.
>> 
>> The kit was $40 and does include surface mount parts.
>> 
>> Its just one of many one chip synthesizers around these days.
>> 
>> Searching to find one I remembered I found:
>> http://www.pongrance.com/super-dds.html
>> 
>> There was a commercial crystal replacement crystal synthesizer,
>> personified by:http://www.aade.com/About_PayPal.html#dfd2 at Almost
>> All 
>> Digital Electronics made specifically for Collins.
>> 
>> That TTL logic circuit probably is still workable if Far Circuits
>> has a 
>> PC board. 74HC CMOS will do the same exact functions as TTL a bit
>> faster 
>> and with far less power consumption. But all the logic it took on
>> several square inches of board these days can be had in a 5 x 7 mm
>> kage, or maybe even smaller.
>> 
>> I have a crystal pack so with my extra crystal socket, I'm covered
>> though I like my FT-857D so well my S-line is rarely connected to
>> power.
>> 
>> 73, Jerry, K0CQ, Technical Adviser to the Collins Radio
>> Association.
>> 
>> 
>> On 8/1/2012 3:40 PM, Dave Brown wrote:
>> >   I'm reminded by these posts that there was a Colins S-line etc
>> crystal
>> > replacement synthesiser article quite some years ago in Ham Radio-
>> has this
>> > idea ever been updated? IIRC that article used basic 7400 series
>> TTL-I'd
>> > expect there's a 'better mousetrap' around these days....
>> >   73
>> >   Dave, ZL3FJ
>> >
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