[GreenKeys] Optimistic but clueless seller

[Marc Howard]

Why are 2m crystals so cherished?  Have we lost the recipe to make them?

We stopped using crystals years ago at work. The silicon synthesizers are
smaller, just about zilch jitter/noise, and you can dial in any frequency
you want.

Marc NC6SU

On Fri, Apr 23, 2021 at 2:45 PM Ralph Mowery <rmowery42 at charter.net> wrote:

>
>
> Maybe it was bought for the value of the tubes.  Did you scroll down and
> look at some of the tube prices ?  Some are around $ 200 or more per tube.
>
> Sort of like some of the old crystal controlled 2 meter rigs .  The set is
> not worth much,but crystals are out of sight pricewise.
>
> Ralph ku4pt
>
>
>
> -----Original Message-----
> From: greenkeys-bounces at mailman.qth.net [mailto:
> greenkeys-bounces at mailman.qth.net] On Behalf Of Robert Nickels
> Sent: Friday, April 23, 2021 11:40 AM
> To: tmc at mailman.qth.net; GreenKeys at mailman.qth.net
> Subject: [GreenKeys] Optimistic but clueless seller
>
> has listed a Northern 153 dual frequency shift keyer with some
> entertaining comments:
>
> https://www.ebay.com/itm/265133627883
>
> The manual can be found on the TMC History site;  custom plug-ins
> determine the tone frequency and the module that can be read is for
> 2167.5 Mark and 2082.5 Space, i.e. 85 kHz spacing.   The front panel tag
> shows another pair to be 2337 and 2252 Hz, also 85 Hz spacing.   So that
> would translate to 153Z12 and 153Z13 modules in this unit.
>
> Frequency-determining modules were sold by center frequency which is
> shifted +/- 42.5 Hz  and recommended 170 Hz channel spacing at 100 wpm,
> and the output of up to 18 channels can be combined. Eighteen keyers
> would fill one rack, then of course you'd need a couple of racks full of
> demodulators on the other end, which is why Northern came out with the
> transistorized version that put all 18 tone keyers and converters in
> less than 16" of rack space:
>
> http://tmchistory.org/NorthernRadio/Manuals/northern_230_235_tm.pdf
>
> It would be interesting to hear what 18 FSK tones would sound like over
> HF but according to the manual, these 18-channel systems were intended
> for use on microwave or wireline circuits.
>
> 73, Bob W9RAN
>
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
> >>> Jordan Spencer Cunningham's GreenKeys Search Tool:
> https://teletype.net/gksearch
> >>> 2002-to-present greenkeys archive:
> http://mailman.qth.net/pipermail/greenkeys/
> >>> 1998-to-2001 greenkeys archive:
> http://mailman.qth.net/archive/greenkeys/greenkeys.html
> >>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool:
> http://comcents.com/tty/greenkeyssearch.html
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to marc.howard at ieee.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20210423/226c8061/attachment.html>