I have a Lavoie Labs WWV Frequency Comparator that is surplus to my
needs. It is s/n 450 but is not marked with the model number,
although I believe it is an LA-800D. I also have a photocopy of the
operation and service manual, including schematic and parts list.
The device gives an oscilloscopic display of the phase difference
between your local frequency standard and the received WWV signal on
either 5 or 15 MHz.
The beast still works although the electrolytics need replacing
(symptom -- one of the power transformers gets very warm after a few
hours of operation). And it could probably benefit from a proper
RF/IF alignment (I have never bothered to do this).
The unit is too big and heavy to ship by any normal means, so "local
pick up only". However, I could meet you "half-way", provided it is
within 200 km of Ottawa, Ontario. Free to a good home.
... Martin VE3OAT
(near Ottawa, Canada)
Had one of those before downsizing. Very clever circuit, if you are
describing the vacuum tube unit.
The small CRT does a circular sweep based on the reference standard with
brightness modulated by the strength of the received signal, so that no
rotation of the half bright half dark pattern proves a match.
From Minnesota, under good conditions, I could see the pattern change
phase between Colorado and Hawaii as propagation conditions changed.
No room for one now, but it was the most interesting WWV receiver I ever
owned.
Disclaimer: Absolutely no relation to Martin - thought you should know
more about its capabilities.
Bill Hawkins
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Martin
VE3OAT
Sent: Saturday, January 07, 2017 3:40 PM
To: time-nuts@febo.com
Subject: [time-nuts] Lavoie WWV Frequency Comparator available
I have a Lavoie Labs WWV Frequency Comparator that is surplus to my
needs. It is s/n 450 but is not marked with the model number, although
I believe it is an LA-800D. I also have a photocopy of the operation
and service manual, including schematic and parts list.
The device gives an oscilloscopic display of the phase difference
between your local frequency standard and the received WWV signal on
either 5 or 15 MHz.
The beast still works although the electrolytics need replacing (symptom
-- one of the power transformers gets very warm after a few hours of
operation). And it could probably benefit from a proper RF/IF alignment
(I have never bothered to do this).
The unit is too big and heavy to ship by any normal means, so "local
pick up only". However, I could meet you "half-way", provided it is
within 200 km of Ottawa, Ontario. Free to a good home.
... Martin VE3OAT
(near Ottawa, Canada)
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi, Bill,
Thanks for adding the extra detail about how this receiver works.
Maybe it will tweak the interest of someone who wasn't already aware
of what it does. I had known of them for years before I found one I
could afford, but that was many years ago. Spent many hours watching
the ellipse and marvelling at the sudden changes of direction as the
phase of the received signal changed. It was my introduction to
Doppler shifting of ionospherically propagated HF signals.
73,
... Martin VE3OAT
On 08/01/2017 01:36, Bill Hawkins wrote:
Had one of those before downsizing. Very clever circuit, if you are
describing the vacuum tube unit.
The small CRT does a circular sweep based on the reference standard with
brightness modulated by the strength of the received signal, so that no
rotation of the half bright half dark pattern proves a match.
From Minnesota, under good conditions, I could see the pattern change
phase between Colorado and Hawaii as propagation conditions changed.
No room for one now, but it was the most interesting WWV receiver I ever
owned.
Disclaimer: Absolutely no relation to Martin - thought you should know
more about its capabilities.
Bill Hawkins
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Martin
VE3OAT
Sent: Saturday, January 07, 2017 3:40 PM
To: time-nuts@febo.com
Subject: [time-nuts] Lavoie WWV Frequency Comparator available
I have a Lavoie Labs WWV Frequency Comparator that is surplus to my
needs. It is s/n 450 but is not marked with the model number, although
I believe it is an LA-800D. I also have a photocopy of the operation
and service manual, including schematic and parts list.
The device gives an oscilloscopic display of the phase difference
between your local frequency standard and the received WWV signal on
either 5 or 15 MHz.
The beast still works although the electrolytics need replacing (symptom
-- one of the power transformers gets very warm after a few hours of
operation). And it could probably benefit from a proper RF/IF alignment
(I have never bothered to do this).
The unit is too big and heavy to ship by any normal means, so "local
pick up only". However, I could meet you "half-way", provided it is
within 200 km of Ottawa, Ontario. Free to a good home.
... Martin VE3OAT
(near Ottawa, Canada)
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.