Back in 1977 there was a circuit published widely that claimed to
correct drift in a vfo by sampling the output, downconverting it,
comparing it with a crystal oscillator then correcting a varicap in
the vfo. Has anyone ever tried this? How well did it work? This
circuit, if it works, could be resurrected and bring a lot of the
older Boatanchor Rigs back on the air. It was called an FLL or
Frequency Locked Loop and was not very complicated.


Tony WA6LZH

On 9 Oct 2003 16:58:37 -0700, Tony Angerame wrote:
Back in 1977 there was a circuit published widely that claimed to
correct drift in a vfo by sampling the output, downconverting it,
comparing it with a crystal oscillator then correcting a varicap in
the vfo. Has anyone ever tried this? How well did it work? This
circuit, if it works, could be resurrected and bring a lot of the
older Boatanchor Rigs back on the air. It was called an FLL or
Frequency Locked Loop and was not very complicated.

Known colloquially as a "Huff and Puff" stabilizer of which PA0KSBs
one is an improved version. There was a simplified version of
PA0KSBs circuit published by G3DXZ, and a faster one by G7IXH.
They were discussed at length in the Radio Society of Great Britains
magazine "Radcom" in 1996 and 97, but that's probably not much help
to you. I believe that G7IXHs version was published in QEX in 1998
if that helps.
--
Cheers,
Stan Barr stanb .at. dial .dot. pipex .dot. com
(Remove any digits from the addresses when mailing me.)

The future was never like this!

On 9 Oct 2003 16:58:37 -0700, Tony Angerame wrote:
Back in 1977 there was a circuit published widely that claimed to
correct drift in a vfo by sampling the output, downconverting it,
comparing it with a crystal oscillator then correcting a varicap in
the vfo. Has anyone ever tried this? How well did it work? This
circuit, if it works, could be resurrected and bring a lot of the
older Boatanchor Rigs back on the air. It was called an FLL or
Frequency Locked Loop and was not very complicated.

Known colloquially as a "Huff and Puff" stabilizer of which PA0KSBs
one is an improved version. There was a simplified version of
PA0KSBs circuit published by G3DXZ, and a faster one by G7IXH.
They were discussed at length in the Radio Society of Great Britains
magazine "Radcom" in 1996 and 97, but that's probably not much help
to you. I believe that G7IXHs version was published in QEX in 1998
if that helps.
--
Cheers,
Stan Barr stanb .at. dial .dot. pipex .dot. com
(Remove any digits from the addresses when mailing me.)

The future was never like this!

"Stan Barr" wrote


Back in 1977 there was a circuit published widely that claimed to
correct drift in a vfo by sampling the output, downconverting it,
comparing it with a crystal oscillator then correcting a varicap in
the vfo. Has anyone ever tried this? How well did it work? This
circuit, if it works, could be resurrected and bring a lot of the
older Boatanchor Rigs back on the air. It was called an FLL or
Frequency Locked Loop and was not very complicated.

Known colloquially as a "Huff and Puff" stabilizer of which PA0KSBs
one is an improved version. There was a simplified version of
PA0KSBs circuit published by G3DXZ, and a faster one by G7IXH.
They were discussed at length in the Radio Society of Great Britains
magazine "Radcom" in 1996 and 97, but that's probably not much help
to you. I believe that G7IXHs version was published in QEX in 1998
if that helps.



**** Hewlett Packard used this principle with the HP8708A Synchroniser
which was used with the HP 606B and HP608F signal generators.It would
lock them down to a very small frequency range.

Brian Goldsmith.

"Stan Barr" wrote


Back in 1977 there was a circuit published widely that claimed to
correct drift in a vfo by sampling the output, downconverting it,
comparing it with a crystal oscillator then correcting a varicap in
the vfo. Has anyone ever tried this? How well did it work? This
circuit, if it works, could be resurrected and bring a lot of the
older Boatanchor Rigs back on the air. It was called an FLL or
Frequency Locked Loop and was not very complicated.

Known colloquially as a "Huff and Puff" stabilizer of which PA0KSBs
one is an improved version. There was a simplified version of
PA0KSBs circuit published by G3DXZ, and a faster one by G7IXH.
They were discussed at length in the Radio Society of Great Britains
magazine "Radcom" in 1996 and 97, but that's probably not much help
to you. I believe that G7IXHs version was published in QEX in 1998
if that helps.



**** Hewlett Packard used this principle with the HP8708A Synchroniser
which was used with the HP 606B and HP608F signal generators.It would
lock them down to a very small frequency range.

Brian Goldsmith.

Known colloquially as a "Huff and Puff" stabilizer of which PA0KSBs
one is an improved version.

A nice web site on this is
http://www.hanssummers.com/radio/huffpuff/contents.htm
There are lots of downloadable papers there also.


Sverre
Asker, Norway
www.qsl.net/LA3ZA

Known colloquially as a "Huff and Puff" stabilizer of which PA0KSBs
one is an improved version.

A nice web site on this is
http://www.hanssummers.com/radio/huffpuff/contents.htm
There are lots of downloadable papers there also.


Sverre
Asker, Norway
www.qsl.net/LA3ZA

Thanks Stan, Brian and Sverre. I think I'll check out the URL for the
simplified and improved version. Good info. I guess if it's simple enough
it's worth a try. I'll let you know if I do and what results.

73 Tony WA6LZH

"Tony Angerame" wrote in message
om...
Back in 1977 there was a circuit published widely that claimed to
correct drift in a vfo by sampling the output, downconverting it,
comparing it with a crystal oscillator then correcting a varicap in
the vfo. Has anyone ever tried this? How well did it work? This
circuit, if it works, could be resurrected and bring a lot of the
older Boatanchor Rigs back on the air. It was called an FLL or
Frequency Locked Loop and was not very complicated.


Tony WA6LZH

Thanks Stan, Brian and Sverre. I think I'll check out the URL for the
simplified and improved version. Good info. I guess if it's simple enough
it's worth a try. I'll let you know if I do and what results.

73 Tony WA6LZH

"Tony Angerame" wrote in message
om...
Back in 1977 there was a circuit published widely that claimed to
correct drift in a vfo by sampling the output, downconverting it,
comparing it with a crystal oscillator then correcting a varicap in
the vfo. Has anyone ever tried this? How well did it work? This
circuit, if it works, could be resurrected and bring a lot of the
older Boatanchor Rigs back on the air. It was called an FLL or
Frequency Locked Loop and was not very complicated.


Tony WA6LZH