[Collins] 851-S1 stability

Fri Sep 23 14:08:27 EDT 2016

I am only somewhat familiar with crystal oscillator stability due to working on KWT-6 stabilized master oscillators.  Somewhat silly to set the KWT-6 reference oscillator with a frequency counter that has the same or somewhat lower stability.  So I bought a Rubidium oscillator off of eBay so hopefully I am able to set the reference oscillator with the frequency counter that is using the Rubidium standard as it's time base reference which is about three orders of magnitude better then the KWT-6 reference oscillator.
According to this chart: https://www.meinbergglobal.com/english/specs/gpsopt.htm, a TXCO can hold 1 X 10-9 for about one second.  For one day, the TXCO stability drops about two orders of magnitude but the Rubidium oscillator is essentially unchanged.  I would think that this TXCO stability of 1 X 10-7 or one cycle per 10 mc is more than adequate to the task of keeping one on frequency.Jim

      From: Dr. Gerald N. Johnson <geraldj at netins.net>
 To: collins at mailman.qth.net 
 Sent: Friday, September 23, 2016 11:11 AM
 Subject: Re: [Collins] 851-S1 stability

I've been digging for the manual and the only thing I came up with was 
at mods.dk and the package didn't include the specifications or the 
operator's manual.

So I was going to say that it takes a really good TCXO to hold 1 x 10-9 
and I found in that manual set that the crystal oscillator is the 
reference so I wouldn't expect it to be that good for drift. It is shop 
adjustable for temperature compensation. I have an HP standard that 
might do 1 x 10-11 with lots of temperature control and an SC cut 
crystal, model 10811. Better than that takes rubidium that's only 
another order of magnitude better. 3 x 10-18 is a million times better 
than can be purchased today.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

On 9/23/2016 10:59 AM, Heinz Breuer wrote:
> Hello Sheldon,
> this is a misprint.
> The -10 Series Supplement, 851S-1 Receiver, 2nd Edition, March 1, 1981 says 3 x 10-8 per week with the standard oscillator or 1 x 10-8 per week with the optional high stability oscillator.
>
> vy 73 Heinz DH2FA, KM5VT
>
> Von meinem iPhone gesendet
>
>> Am 23.09.2016 um 16:18 schrieb Sheldon Daitch<SDAITCH at bbg.gov>:
>>
>> Because of Heinz' posting of his 851-S1, I looked at this link:
>>
>> http://www.collinsradio.org/cca-collins-historical-archives/the-equipment-of-collins-radio/the-s-word-or-solid-state/851s-1/
>>
>> to refresh my memory on this unit and noted this specification under frequency stability:
>>
>> Drift rate not more than 3 x 10-18 per week.
>>
>> Ten to the minus 18?  That can't be right, can it?
>>
>>
>> 73
>>
>> Sheldon
>>
>> [http://www.collinsradio.org/wp-content/uploads/2012/08/851S1ax.gif]<http://www.collinsradio.org/cca-collins-historical-archives/the-equipment-of-collins-radio/the-s-word-or-solid-state/851s-1/>
>>
>> 851S-1 | Collinsradio<http://www.collinsradio.org/cca-collins-historical-archives/the-equipment-of-collins-radio/the-s-word-or-solid-state/851s-1/>
>> www.collinsradio.org
>> HOME; ABOUT; JOIN US; ARCHIVES; SIGNAL; RX For Your Collins; REFLECTOR; MEMBER LOGIN; MANUALS; 851S-1. THE COLLINS 851S-1 RECEIVER. The Rockwell-Collins 851S-1 is the ...
>>
>>
>>
>>
>> ________________________________
>> From: Collins<collins-bounces at mailman.qth.net>  on behalf of Heinz Breuer<hbreuer at debitel.net>
>> Sent: Wednesday, September 21, 2016 5:58 AM
>> To: collins at mailman.qth.net
>> Subject: [Collins] For sale Rockwell-Collins 851S-1 receiver
>>
>> Hello,
>> out of my personal collection I have available for sale a Rockwell-Collins 851S-1 Receiver.
>>
>> The 851S-1 has 7 Collins mechanical filters and offers bandwidths 0.2 kHz, 0.5 kHz, 1 kHz, 3 kHz, 6 kHz, LSB and USB as well as 16 kHz due to the roofing filter. The receiver has modes SSB, CW, AM.
>> Tuning step is 10 Hz.
>>
>> There are no optional boards installed: No IF Channel B, no VBFO, no AFC, no Parallel IN, no Parallel OUT, no Serial card and no high stability oscillator.
>> I do have a couple optional boards these can be purchased at additional cost.
>>
>> Pictures are available on request.
>>
>> Overall condition is very good to excellent, no marks on the front panel, a few smaller scratches on the top and bottom cover due to rack mounting. The VFO knob insert has a couple light scratches and small marks.
>>
>> The 851S-1 is in fully working condition.
>>
>> Price is $ 1.200
>>
>> I will ship worldwide with DHL Express as fully insured parcel. I will pack very carefully in a strong triple wall export box (10mm wall thickness) with styrofoam cushioning.
>>
>> Please ask for shipping charges to your destination. As a hint expect about $ 220 shipping to the US.
>>
>> vy 73 de Heinz DH2FA, KM5VT
>>
>> Von meinem iPhone gesendet
>>
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