[ARC5] The not-so humble BC-221/LM-xx frequency meters. - zero-beating with WWV
Spencer Petri
petewa5jci at gmail.com
Sat Dec 24 17:23:19 EST 2016
Back in the 80s Bob, K7IRK and myself went to the Dallas sidewalk sale
before there was a cost to vendors. Many hams would show up with just
a few items. So we began a competition to see who could buy the most
BC-221s for $5 or less. Many were 3 or 3 dollars. I should have tried
to collect every model made but passed that up, I still have quite a
few of them. They are remarkable machines for their time period.
Probably the best buy was a beautiful $10 ART-13.
de Pete WA5JCI
On 12/24/16, Richard Knoppow <1oldlens1 at ix.netcom.com> wrote:
> There is a brief history of time keeping at:
> https://www.nist.gov/pml/time-and-frequency-division/popular-links/walk-through-time
>
> Time was determined primarily by astronomical means.
> There is a great deal of other information on the web.
> I think NBS had descriptions and papers on their early time
> standards. I have not looked but would expect them to be on the NIST site.
> WWV and other HF standard stations can be received with very high
> accuracy by time averaging over a sufficiently long period. The various
> propagation errors are averaged out. Much more stable transmission is
> to be had on LF and VLF but averaging is still necessary. ELF is phase
> stable over the surface of the earth but I think only available from a
> couple of Navy stations. References from GPS satellites beats this and
> is much easier to use.
>
> On 12/24/2016 12:04 PM, Arden Allen wrote:
>> I'm more interested in Howard's question about frequency standards in
>> general. Just how did NBS come up with frequency standards before the
>> age of atomic time standards and digital counters?
>>
>> Arden Allen
>> KB6NAX
>>
>
>
> --
> Richard Knoppow
> 1oldlens1 at ix.netcom.com
> WB6KBL
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