EMRFD Message Archive 37
Message Date From Subject 37 2006-07-25 15:50:10 Pete Eaton VFO Options Several folks have mentioned the challenge in
procuring variable capacitors and reduction drives
that can tune the entire band while staying within
budget.
A PTO might be an option to consider. WA6OTP offers
one possible solution:
http://www.wa6otp.com/pto.htm
Given it's 500 KHz tuning range one can easily cover
the entire 40 meter band with no reduction drive
needed.
Adding a simple digital display like Wolf DL4YHF's
single PIC Freq Counter offers one possible solution:
http://www.qsl.net/dl4yhf/freq_counter/freq_counter.html
While I have no experience with PTO's several
manufactures used them successfully for many years
with
excellent results.
On the other hand if someone can design a $5.00
DDS/PLL VFO with no spurs.......
Pete WB9FLW
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http://mail.yahoo.com39 2006-07-28 20:10:08 Stan Re: VFO Options Hi Pete, the WA6OTP PTO is a good circuit, One needs to do a
little mechanical work to come up with a neat tuning method.
It is easy to change the frequency to other values, standard LC
calculations.
Stan ak0b
41 2006-07-29 12:12:13 zx97lite Re: VFO Options Hi Stan,
Found the following PTO mechanical design on the BITX20 Yahoo Group:
http://f1.grp.yahoofs.com/v1/IKLLRKjPLkOj6mTRQ8EqfRFAG34jF5bdRISd9SbDbAedQ5iKIP1cx6Xr5MQrDcwWcZRTGhZgY_-Sqw5TOtDq6RqdIRxGnuU/K7HKL/PTO_Simplified_Mechanicals%28K7HKL%29.png
On WA6OTP's design he claims 13 KHz per revoluti42 2006-07-29 14:18:29 Roy J. Tellason Re: VFO Options On Saturday 29 July 2006 03:11 pm, zx97lite wrote:
> Hi Stan,The link doesn't work. Looks like one of those "dynamically generated" links
>
> Found the following PTO mechanical design on the BITX20 Yahoo Group:
>
> http://f1.grp.yahoofs.com/v1/IKLLRKjPLkOj6mTRQ8EqfRFAG34jF5bdRISd9SbDbAedQ5
>iKIP1cx6Xr5MQrDcwWcZRTGhZgY_-Sqw5TOtDq6RqdIRxGnuU/K7HKL/PTO_Simplified_Mecha
>nicals%28K7HKL%29.png
that yahoo is so fond of using for stuff...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin43 2006-07-30 00:54:28 Stan Re: VFO Options Now : BITX project comments 44 2006-07-30 10:24:52 zx97lite Re: VFO Options Hi Roy,
Sorry for the confusion.
Go to the BITX20 Yahoo Group.
Under BITX20 Files there is a "K7HKL BITX Tools" Directory, there you
will find:
"PTO_Simplified_Mechanicals(K7HKL).png"
Let me know if you have any problems.
Best Wishes,
Pete WB9FLW
45 2006-07-30 11:00:26 Roy J. Tellason Re: VFO Options 49 2006-07-31 18:07:46 Roy J. Tellason Re: VFO Options On Sunday 30 July 2006 01:51 pm, Roy J. Tellason wrote:
> On Sunday 30 July 2006 01:21 pm, zx97lite wrote:Got it, and thanks.
> > Hi Roy,
> >
> > Sorry for the confusion.
> >
> > Go to the BITX20 Yahoo Group.
> >
> > Under BITX20 Files there is a "K7HKL BITX Tools" Directory, there you
> > will find:
> >
> > "PTO_Simplified_Mechanicals(K7HKL).png"
> >
> > Let me know if you have any problems.
> >
> > Best Wishes,
> >
> > Pete WB9FLW
>
> I'm apparently "pending" for now...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin