[time-nuts] Lavoie WWV Frequency Comparator available

[Martin VE3OAT]

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 at febo.com] On Behalf Of Martin
> VE3OAT
> Sent: Saturday, January 07, 2017 3:40 PM
> To: time-nuts at 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)
>
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