[Collins] 32S-1 unknown mod

[Carl]

Thanks Jerry.

What I do remember in the early 60's was S Line and a RTTY unit in place at 
several USAF MARS/ham stations I visted while in the USN. Mostly in the Med.

I have no idea what model S Line or anything about the RTTY at the 
time....it might have been a Model 28; we were still using the Model 15 on 
the WW2 Fleet Oiler I was on.

As an ET I didnt have to service them.....thankfully!

Carl
KM1H


----- Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj at netins.net>
To: <collins at mailman.qth.net>
Sent: Saturday, March 08, 2014 5:58 PM
Subject: Re: [Collins] 32S-1 unknown mod


> AM. RTTY was sometimes mentioned using an added shifter in the PTO or 
> changing the bias drive on the USB/LSB shifter in the PTO. Sometimes the 
> added shifter was connected using a tube socket test extender under the 
> PTO tube. I'm sure not beneficial to frequency stability. W5USI says it 
> was suggested at Collins. I know it was published in RTTY magazine in 
> those days. I have a copy somewhere.
>
> Most RTTY was run using audio tones, for 850 shift the tones users were 
> 2125 and 1275 because the RTTY standard high tone of 2975 wouldn't pass 
> through the SSB filter and without taking out the capacitor on the plate 
> of the receiver audio output tube 2975 was weak. Hence the "Collins tones" 
> of 1275 and 2125. 2125 and 2975 were used for AFSK beginning in amateur 
> RTTY on FM (the first mode it was allowed on) using pairs of surplus 
> telephone company filters. Now with 170 shift most common saving spectrum 
> and usually working better and with computers doing the copying and 
> creating the transmit tones, any tone pair that passes through the filters 
> works, though its probably worth the slight bother to keep the tones above 
> 1/2 the upper audio cutoff frequency through the transmit filter to 
> minimize spurious outputs if the transmit tones have harmonics or the 
> audio is over driven.
>
> Long about 40 years ago I created the audio tones using a unijunction 
> transistor oscillator with equal rise and fall slopes srranged so that 
> keying changed only the slope (and hence the frequency) with no other 
> keying transients. The triangular wave form compared to a square wave or 
> sawtooth had only 8% total harmonic distortion which was cleaner than 
> those more common digital waveforms. Keying an LC audio oscillator tended 
> to have some envelope transients at the time of the keying that caused 
> splatter when used for transmitting RTTY through a SSB transmitter.
>
> 73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.
>
> On 3/8/2014 3:43 PM, Carl wrote:
>> AM or RTTY?
>>
>> Carl
>> KM1H
>>
>>
>> ----- Original Message ----- From: "Bill Riches" 
>> <bill.riches at verizon.net>
>> To: <collins at mailman.qth.net>
>> Sent: Saturday, March 08, 2014 4:12 PM
>> Subject: [Collins] 32S-1 unknown mod
>>
>>
>>> Just obtained a clean 32s-1 that has a mod in it that I have not seen. I
>>> have not fired up the unit yet. Pin 6 of v2 plate of BFO osc is 
>>> connected
>>> to a 100 k pot thru a 51 pf cap. The wiper of the pot is connected to
>>> p7 of
>>> V4 first mixer through a 100 pf cap in series with a 22k resistor. The
>>> 100
>>> k pot is mounted on the same type of add-on bracket that is used for
>>> the vox
>>> time const control mod. The knob on this control is identical to the
>>> other
>>> knobs on the other three controls. Workmanship is first class. Is this a
>>> Collins mod? What is it for? Inquiring mimes want to know!
>>>
>>>
>>>
>>> 73,
>>>
>>> Bill, WA2DVU
>>>
>>> Cape May, NJ
>>>
>>>
>>>
>>> .
>>>
>>>
>>>
>>> ______________________________________________________________
>>> Collins mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/collins
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Collins at mailman.qth.net
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>>
>>> -----
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2014.0.4335 / Virus Database: 3722/7168 - Release Date: 
>>> 03/08/14
>>>
>>
>> ______________________________________________________________
>> Collins mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/collins
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Collins at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
>
> ______________________________________________________________
> Collins mailing list
> Home: http://mailman.qth.net/mailman/listinfo/collins
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Collins at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4335 / Virus Database: 3722/7168 - Release Date: 03/08/14
>