On 2/15/17 3:07 PM, Alberto di Bene wrote:
On 2/15/2017 5:29 PM, Tim Shoppa wrote:
For those of us who have to translate between the old "cps" and the
modern
"Hz", I found this handy conversion table on the web:
http://www.aqua-calc.com/convert/frequency/hertz-to-cycle-per-second
Tim N3QE
Na
On 2/15/2017 5:29 PM, Tim Shoppa wrote:
For those of us who have to translate between the old "cps" and the modern
"Hz", I found this handy conversion table on the web:
http://www.aqua-calc.com/convert/frequency/hertz-to-cycle-per-second
Tim N3QE
Nahhh this is much better :-)
http:/
Another nice example of "before there were frequency counters":
"Methods of using standard-frequency radio transmissions", 1934
http://tf.nist.gov/general/pdf/2423.pdf
"Recent developments in precision time-keeping", 1934
http://leapsecond.com/pend/pdf/1934-Tomlinson-Recent-Development
It may be that they were all once regarded as Wavemeters, i.e. for
measuring wavelength, but there was a distinction that is often
dropped... the Absorption Wavemeter, as opposed to the "normal" variety.
Much like a video recording almost universally referred to as a
"video"... a video what?
>>> Messaggio originale
>>> Da: "Tim Shoppa"
>>> Data: 15/02/2017 17.29
>>> A: "Discussion of precise time and frequency
>>> measurement"
>>> Ogg: Re: [time-nuts] Vintage Frequency Measurement
>>>
>>
;Discussion of precise time and frequency measurement"
>> Ogg: Re: [time-nuts] Vintage Frequency Measurement
>>
>> For those of us who have to translate between the old "cps" and the modern
>> "Hz", I found this handy conversion table on the web:
>>
;Discussion of precise time and frequency measurement"
>Ogg: Re: [time-nuts] Vintage Frequency Measurement
>
>For those of us who have to translate between the old "cps" and the modern
>"Hz", I found this handy conversion table on the web:
>http://www.aq
For those of us who have to translate between the old "cps" and the modern
"Hz", I found this handy conversion table on the web:
http://www.aqua-calc.com/convert/frequency/hertz-to-cycle-per-second
Tim N3QE
[image: Inline image 1]
On Tue, Feb 14, 2017 at 5:29 AM, Peter Vince
wrote:
> On 14 Feb
ebo.com>
> Sent: Monday, 13 February 2017, 23:46
> Subject: Re: [time-nuts] Vintage Frequency Measurement
>
> Hi
>
> With a VFO running, you have a heterodyne frequency meter. That is (at
> least to me)
> a very different device than an absorption wave meter. I know wa
t Atkinson; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Vintage Frequency Measurement
Hi
The link gives an error, but I have no doubt that the meaning of the term
varies a bit.
Thanks for the reference. I’ll try to get it working from here.
Bob
> On Feb 15, 201
; Sent: Monday, 13 February 2017, 23:46
> Subject: Re: [time-nuts] Vintage Frequency Measurement
>
> Hi
>
> With a VFO running, you have a heterodyne frequency meter. That is (at least
> to me)
> a very different device than an absorption wave meter. I know way to put
>
ent: Monday, 13 February 2017, 23:46
Subject: Re: [time-nuts] Vintage Frequency Measurement
Hi
With a VFO running, you have a heterodyne frequency meter. That is (at least to
me)
a very different device than an absorption wave meter. I know way to put power
into
a BC-221 and use it as an ab
On 14 February 2017 at 04:23, Raj wrote:
> I have a Marconi T.F. 643 C, in Megacycles !
>
Ah, a sensible, descriptive name for the unit. Some of these modern units
really do Hert(z) :-)
Peter
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To u
HI
What frequency is the crystal and what sized package is it in?
Bob
> On Feb 14, 2017, at 11:20 AM, Scott Stobbe wrote:
>
> Taking a second look in the manual, they specifically call out that its not
> an AT or BT, so I'm not sure what it would be.
>
> Interestingly they describe the therm
Hi
That was one of the reasons I was a bit amazed high school students
were doing it as a lab exercise. The presence of high voltage here and
there is something that you simply would not see in a similar school
today …
Bob
> On Feb 13, 2017, at 11:19 PM, Alex Pummer wrote:
>
> just be careful
just be careful, because if you under-heat the cathode you could kill it
73
Alex
On 2/13/2017 7:11 PM, Bob Camp wrote:
Hi
On Feb 13, 2017, at 8:15 PM, Scott Stobbe wrote:
On Mon, Feb 13, 2017 at 6:41 PM, Bob Camp wrote:
I think what you would find is that it *is* a fairly normal AT c
Hi
> On Feb 13, 2017, at 8:15 PM, Scott Stobbe wrote:
>
> On Mon, Feb 13, 2017 at 6:41 PM, Bob Camp wrote:
>
>>
>>
>> I think what you would find is that it *is* a fairly normal AT cut and the
>> data book
>> that came with the instrument plotted out the data for the specific
>> crystal in
On Mon, Feb 13, 2017 at 6:41 PM, Bob Camp wrote:
>
>
> I think what you would find is that it *is* a fairly normal AT cut and the
> data book
> that came with the instrument plotted out the data for the specific
> crystal in
> the device. The usable temperature range was fairly small, so the plot
nts.
-- john, KE5FX
Miles Design LLC
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
> Camp
> Sent: Monday, February 13, 2017 3:47 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Vint
Hi
> On Feb 13, 2017, at 10:35 AM, Scott Stobbe wrote:
>
> Hi Mike,
>
> First of all, Wow what an interesting read, thanks for sharing some of the
> history and your experiences with the 105. A second thanks for uploading
> the manual, which I found to be a great read, as with most old test &
Hi
With a VFO running, you have a heterodyne frequency meter. That is (at least to
me)
a very different device than an absorption wave meter. I know way to put power
into
a BC-221 and use it as an absorption device.
I’m not in any way saying that the LM or the 221 are less useful. They are
st
You could use it as an absorption wavemeter, in its broadest sense of a passive
tuned circuit with an indicating load. The headphone jack was normally used to
calibrate the VFO against a harmonic of the internal crystal oscillator, but it
could zero beat an external source as well. It stretche
On 2/13/2017 12:56 PM, Brooke Clarke wrote:
Wes: Is this the patent for the IMPATT diode power amplifier?
https://patents.google.com/patent/US3931587
No. As I recall the designer (or at least a prime mover) was a guy named
Eisenhart. The Hughes organization at the time had engineering done
On 02/13/2017 10:35 AM, Scott Stobbe wrote:
Hi Mike,
First of all, Wow what an interesting read, thanks for sharing
some of the history and your experiences with the 105. A second
thanks for uploading the manual, which I found to be a great
read, as with most old test & measurement product manu
The BC-221 was the backbone of WW2 communications. How else were all
those sloppy BC-348's and AR-13's set to the called-for frequencies?
Same for shipboard.
Don
On 2017-02-13 13:05, Brooke Clarke wrote:
Hi Bob:
The BC-221 is usually referred to as either a Frequency Meter or a
Heterodyne F
Hi Bob:
The BC-221 is usually referred to as either a Frequency Meter or a Heterodyne
Frequency Meter.
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
Original Message
Hi
Ok, so how does that make a BC-221 a wave meter?
B
on an unusual frequency (not a normal route) for which they did
not have a crystal available.
Alan
G3NYK
- Original Message - From: "Dan Rae"
To: "Discussion of precise time and frequency measurement" <
time-nuts@febo.com>
Sent: Sunday, February 12, 2017 11:11 PM
Sub
On Sun, Feb 12, 2017 at 8:39 AM, Dan Rae wrote:
> On 2/11/2017 10:08 PM, Scott Stobbe wrote:
>
>> I was inspired recently coming across a Lampkin 105 frequency meter, as to
>> how frequency measurement was done before counters.
>>
>> Certainly zero-beating a dial calibrated oscillator, would be
This reminds me.
Many years ago the Titan Missile sites around here in Tucson were being
decommissioned. The people at Davis Monthan AFB who maintained them were going
to be out of work but had an opportunity to bump into something else on base if
they got some more training. I and a coworke
The BC-221 was mentioned in a Time-Nuts thread from December, 2015.
Copying from my post in that old thread:
Back in the early 1970's I took my BC-221 and added a TTL divide by
1,000 (or 2,000 or 4,000 or 8,000) external circuit to generate very
precise audio test tones from the RF oscillator. The
Hi
Ok, so how does that make a BC-221 a wave meter?
Bob
> On Feb 12, 2017, at 7:15 PM, Wes wrote:
>
> On 2/12/2017 12:51 PM, Bob Camp wrote:
>> Hi
>>
>> Maybe I’ve been wrong for the last many decades …
>>
>> To me a wave meter is a tuned circuit device that tells you the frequency by
>> a
d
>> not have a crystal available.
>>
>> Alan
>> G3NYK
>> - Original Message ----- From: "Dan Rae"
>> To: "Discussion of precise time and frequency measurement" <
>> time-nuts@febo.com>
>> Sent: Sunday, Feb
Hi
If you look at a typical BC-221 in use, it goes from “calibrated” in a nice
warm hut to the back
of a jeep. It heads out to an ice cold flight line and the switch turns the
batteries back on again.
It bumps in and out of a batch of B-17’s setting each one up for the day’s net
frequencies. Y
On 12 February 2017 at 06:08, Scott Stobbe wrote:
> I was inspired recently coming across a Lampkin 105 frequency meter, as to
> how frequency measurement was done before counters.
>
> Certainly zero-beating a dial calibrated oscillator, would be one approach.
>
> Is there a standout methodology
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Sunday, February 12, 2017 11:11 PM
> Subject: Re: [time-nuts] Vintage Frequency Measurement
>
>
> To put BC-221 things in perspective, the 1 Mc/s reference cry
r lines or cavity wavemeters.
Robert G8RPI.
From: Scott Stobbe
To: Discussion of precise time and frequency measurement
Sent: Sunday, 12 February 2017, 6:08
Subject: [time-nuts] Vintage Frequency Measurement
I was inspired recently coming across a Lampkin 105 frequency meter,
> More recently, Alan Melia, G3NYK, reports an accuracy of 0.1 Hertz using
> the same technique, http://www.alan.melia.btinternet.co.uk/freqmeas.htm .
John -- Alan's web site moved from btinternet to http://g3nyk.ham-radio-op.net/
so the new URL is:
"Frequency and Time Measurement"
http://g3
Well 5 cycles per second is more than accurate enough. That translates to a
150 Hz error at 30 MHz, definitely negligible for the uses of all these gear.
There was no official Time Nuts group at the time, although many of us had the
spirit. Yet the capability of the BC-221 far exceeded its sp
for which they did
not have a crystal available.
Alan
G3NYK
- Original Message -
From: "Dan Rae"
To: "Discussion of precise time and frequency measurement"
Sent: Sunday, February 12, 2017 11:11 PM
Subject: Re: [time-nuts] Vintage Frequency Measurement
To put BC-22
Hi
That’s not the *accuracy* of the crystal mind you. That’s how close you do the
zero
beat to something else that is more accurate. The crystal is out in the open
and it
drifts quite a bit as the unit warms up or changes temperature due to being
moved
around.
Bob
> On Feb 12, 2017, at 6:1
To put BC-221 things in perspective, the 1 Mc/s reference crystal was
adjusted, according to the manual, to within 5 c/s...
Things have come a ways since!
Dan
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On Sun, 12 Feb 2017 17:16:18 + (UTC), you wrote:
>In a word,Wavemeters. Classic US onwas the BC221 with built in 100kHz crystal
>calibrator
A couple of years ago, I got a BC221 from an estate; had to recap the
homebrew power supply the late ham had built for it, but the BC221 worked
fine and
uary 12, 2017 2:49 PM
Subject: Re: [time-nuts] Vintage Frequency Measurement
A more accurate way to adjust for zero beat is to tone modulate one of the
signals. The waxing and waning of the tone is easier to discern than for the
background noise.
"Accurate Zero Beating, another perspective
sion of precise time and frequency measurement ;
Bob Albert
Sent: Sunday, February 12, 2017 2:49 PM
Subject: Re: [time-nuts] Vintage Frequency Measurement
A more accurate way to adjust for zero beat is to tone modulate one of the
signals. The waxing and waning of the tone is easier to disce
ginal Message -
> From: "Bob Albert via time-nuts"
> To: "Discussion of precise time and frequency measurement"
>
> Sent: Sunday, February 12, 2017 5:00 PM
> Subject: Re: [time-nuts] Vintage Frequency Measurement
>
>
> > First you need a standard, a
see Radio Laboratory Handbook by
Scroggie.
Ah and the BC-221..
Alan
G3NYK
- Original Message -
From: "Bob Albert via time-nuts"
To: "Discussion of precise time and frequency measurement"
Sent: Sunday, February 12, 2017 5:00 PM
Subject: Re: [time-nuts] V
A more accurate way to adjust for zero beat is to tone modulate one of the
signals. The waxing and waning of the tone is easier to discern than for the
background noise.
"Accurate Zero Beating, another perspective.
When trimming an oscillator so it or one of its harmonics zero beats with WWV
o
DaveB, NZ
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike
> Garvey
> Sent: Monday, 13 February 2017 2:36 a.m.
> To: 'Discussion of precise time and frequency measurement'
> Subject: Re: [time-nuts] Vintage Frequency
So far all the answers are about high-end expensive equipment. There were
also low cost frequency meters. I have one 40 years ago that was not
expensive. It wa a simple "frequency to voltage" circuit that drove an
analog meter. It was made just before the digital multimeters came out,
maybe i
als.org.uk/photos/classDno1.htm
>
> For UHF and Microwave it was Lecher lines or cavity wavemeters.
> Robert G8RPI.
>
>
> From: Scott Stobbe
> To: Discussion of precise time and frequency measurement
> Sent: Sunday, 12 February 2017, 6:08
> Subject: [time-nuts]
[Hopefully this time my post is in the required plain-text format!]
The solid-state HP-5210A and its vacuum-tube predecessors, the
HP-500A/B/C family, were analog frequency measuring instruments. The
circuitry summed the input frequency (converted into pulses) and
generated an analog voltage t
First you need a standard, a crystal oscillator. If you want serious
precision, you'd have one in an oven. Zero beat that with WWV. Then make a
very stable VFO and calibrate the harmonics against the crystal. Assume linear
calibration on the VFO between check points.
The military LM and BC-2
From: Scott Stobbe
To: Discussion of precise time and frequency measurement
Sent: Sunday, 12 February 2017, 6:08
Subject: [time-nuts] Vintage Frequency Measurement
I was inspired recently coming across a Lampkin 105 frequency meter, as to
how frequency measurement was done befor
There was also one generator which you could tune to beat the frequency
in question the generator was a frequency synthesizer without any
digital part that was the famous Schomandl FD! see here
SCHOMANDL-FD1-FDM1 FREQUENCY METER,
https://elektrotanya.com/schomandl-fd1-fdm1_frequenc
and frequency measurement
Subject: Re: [time-nuts] Vintage Frequency Measurement
Back in the early sixties I worked in a lab adjusting filters for line
transmission.
We had numerous oscillators, built to be boat anchors, and CROs set up for X-Y
display.
The lab had 100hz, 1kHz, 10kHz standards
Hi
Counters go back at least into the early 1950’s. I started out with fully
vacuum
tube (except for diodes) counters obtained as surplus in the mid 1960’s. They
used some odd gas filled triodes. Everything in them could have been on the
market
in 1947. They were not a common thing until the la
On 2/11/2017 10:08 PM, Scott Stobbe wrote:
I was inspired recently coming across a Lampkin 105 frequency meter, as to
how frequency measurement was done before counters.
Certainly zero-beating a dial calibrated oscillator, would be one approach.
Google BC-221 and you may get some idea of how
Back in the early sixties I worked in a lab adjusting filters for line
transmission.
We had numerous oscillators, built to be boat anchors, and CROs set up for X-Y
display.
The lab had 100hz, 1kHz, 10kHz standards wired in.
We were expert at recognising lisajou figures. We might have several
osc
Hi,
With low-pass filters, I think.
This is the simplest method: an rc filter and measure is done on the
capacitor poles.
Ilia.
On 02/12/17 06:08, Scott Stobbe wrote:
I was inspired recently coming across a Lampkin 105 frequency meter, as to
how frequency measurement was done before counters
I was inspired recently coming across a Lampkin 105 frequency meter, as to
how frequency measurement was done before counters.
Certainly zero-beating a dial calibrated oscillator, would be one approach.
Is there a standout methodology or instrument predating counters?
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