[GreenKeys] Odd FSK values...

[Kenneth Gartland]

Hi all!

Tks Jim for the excellent description of this
frequency shift & overview of the TU operation...

I think he (Jim), is correct in saying "Tuneable" filters such
as those found in the W2PAT TU design, using the TV
horizontal width coils, mite work for those odd value
shifts like those with DDK WX transmissions...

Probably not many RTTY enthusiasts are using
TU's like these early designs anymore, so I am
thinking the Dovetron TU and perhaps the modfied
CV89's can decode these odd shift values...

Perhaps someone on the list cud try the WX svc
with the 85hz shift to see if they can take copy...

Back to Jim's mention of the "Tunable" filters...

I was looking at those TV width coils in the W2PAT
TU, and they have a very large amount of adjustment
range, and with additional capacitance padding,
mite work on these very narrow shifts...

I know the W2PAT design can be equipped with
a switch to cut extra capacitance in or out to permit
the now standard 170hz shift to be decoded...

I am still working on the unit I got from Jim,
so this is a must do change, as it is presently
tuned for 850hz...

It is an interesting design, and back in the day,
much copy was taken with them and a lot
were in use...

Cheers!

Ken
VE3-HMQ
i-Telex 61663
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