In article , Dave Heil
writes:
Len Over 21 wrote:
In article , Dave Heil mother inferior
writes:
Len Over 21 wrote:
In article . net,
"KØHB"
writes:
"Len Over 21" wrote
None of that elaborate U.S. subdivision would be possible without
the modern frequency synthesizers ....
Wrong again, kind elderly Sir.. "modern frequency synthesizers" first
appeared in amateur radio equipment in the 80's, a couple of decades
after the imposition of "elaborate U.S. sub-division" in 1968.
Hans is correct about amateur HF gear. Len is completely mistaken on the
subject.
Tsk, tsk, crusty old sea salt.
Frequency synthesizers began appearing in many radio services in
the early 1960s.
Yet they were not at all common in amateur radio. More important, those that
existed were not "modern" frequency synthesizers.
The claim made by Len was:
"None of that elaborate U.S. subdivision would be possible without the modern
frequency synthesizers ...."
which is clearly false because the "subdivision" existed any synthesizers as a
necessary condition.
All it took for a ham to stay inside the subbands was a frequency standard of
known accuracy. This could take the form of an accurately-calibrated receiver,
transmitter or transceiver, an external frequency meter (WW2 surplus BC-221 and
LM units were relatively inexpensive in the 1960s) or a 100 kHz oscillator with
suitable dividers.
It should be remembered, too, that in the early 1950s the amateur 160 meter
band was subdivided into eight 25 kHz subbands. There was a complex system of
subbands, showing allowed use by hams depending on location, frequency and time
of day. It was by far the most complex system of "subdivision" in amateur
radio, it required hams to stay within 25 kHz subbands, and it predated the
1960s by almost a decade.
In amateur radio they began with homebuilts since
the offshore manufacturers hadn't gotten around to putting those into
amateur transceivers until the late 70s. :-)
Incorrect on many points.
There were homebrew amateur synthesizers in use as early as 1962 (see QST for
October, 1962, "The Ultimate Exciter", by Clifford Harvey, W1RF, and December,
1964 "A Crystal VFO With Full-Band Coverage" by Frank Noble, W3QLV, to name
just two).
These units were "analog" synthesizers using heterodyne techniques. They were
very complex, physically large and required a large number of quartz crystals
on exact frequencies. The W1RF unit uses 30 crystals, four oscillators, three
mixers and elaborate bandswitching in the synthesizer section alone. The W3QLV
unit (which I owned from about 1985 to 1995) was less complex but still
required 35 crystals on exact frequencies just to cover the 80 meter amateur
band.
While within the capabilites of the advanced homebrewing amateur, they never
became popular for reasons explained below.
In 1963, the manufactured B&W 6100 transmitter appeared on the market, with a
heterodyne-type frequency synthesizer built in. It was not a commercial
success, due in part to its high cost and lack of a matching receiver.
Besides cost, size and complexity considerations, those 1960s-era synthesizers
were unpopular with hams for a very fundamental reason: They did not reflect
the way hams operate on HF/MF.
Most "other services" are channelized or operate on specific predetermined
frequencies. They need equipment that can be set to a specific frequency, and
stay there, without the need to interpret a dial. Being able to tune through a
band is not an important consideration. The "user interface" for these
synthesizers (such as found in the military R-1051 receiver, the B&W 6100
transmitter, and the above homebrew units) is a set of switches for each digit
of the frequency. Which works fine for operating on predetermined frequencies
but very inferior to a simple mechanical "one knob" dial for tuning through a
band looking for a clear spot or other QSOs. This user interface issue was
resolved by making synthesizers that could emulate a mechanical "one knob"
dial.
Additionally, the stability, precision and accuracy of self-controlled
variable-frequency oscillators in quality 1960s amateur equipment such as Drake
and Collins was more than adequate for amateur purposes when used by a skilled
operator.
One more point: Frequency synthesizers *did* become popular in amateur *VHF FM*
gear in the early-mid 1970s. This was driven by the channelized nature of
repeater operation. US manufacturers such as Heath with the HW-2036 produced
amateur transceivers with true modern PLL synthesizers.
Ohhhhhhhh--many radio services! They weren't at all common in amateur
radio, Leonard.
For the precise reasons mentioned above.
Well, if that's true then it shows that amateurs were indeed Behind
The Times insofar as ready-made radios goes... :-)
Not at all. The available 1960s frequency synthesizers simply did not meet
amateur requirements.
Then that wasn't the point, was it?
The claim made by Len was:
"None of that elaborate U.S. subdivision would be possible without the modern
frequency synthesizers ...."
which has clearly been proved to be false. Len was wrong, mistaken, in error,
out in left field. He won't admit it, of course, but it is a clear fact
nonetheless.
Now if you are going to make a great big federal case out of this
little thing, then feel free. :-)
Do you mean if he wants to nit-pick over the fact that you were wrong?
It's not nit-picking. Just plain facts.
Who was wrong? Not I.
Yes, you--beyond the shadow of a doubt.
As proved here.
Radio amateurs were quite
capable of staying within the sub-bands authorized them prior to the
period mentioned by you. Deal with it.
Exactly. A 100/50/25 kHz frequency standard could be built with three tubes in
the early 1960s. By the late 1960s it could be done with a few ICs. There was
no need for synthesizers just to stay in the band.
You seem to need an argument
subject and want to go many rounds on this? Not for me. Waste
of time for me.
Then Len should just admit he was wrong and move on.
I was in the lab and in the field regarding
frequency
synthesizers long ago, know their theory and know both their good
things and bad things of their internals.
Completely irrelevant to the claim that:
"None of that elaborate U.S. subdivision would be possible without the modern
frequency synthesizers ...."
which has been shown to be false.
73 de Jim, N2EY
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