At 17:23 1997-12-12 +0100, Rich Measures wrote:
>>Exactly how, did you do that Rich?
>I used two**, double-filter receivers whose -60db bandwidth was <3.6kHz.
>For a 2.4kHz transmitted bandwidth signal, I compared the signal strength
>on frequency to the signal strength 3.6kHz above or below the signal
>being measured. For measuring a LSB signal, I measure the signal level
>up 3.6KHz. For measuring an USB signal, I measure the signal level down
>3.6 kHz. The offset must be such that it separates edge of the transmit
>window skirt from the edge of the receive window skirt by roughly 40db.
>If the two windows overlap, the relative measurements are not going to be
>accurate.
>>What point in the the speech envelope did you use as reference?
>The detector was the S-meter/AGC circuitry, which normally uses a peak
>detector.
>>What word/phrase was used?
>Ordinary speech, but NO swear words.
Daffys never swear, as they have no reason to...;)
>>How did you establish a constant reference?
>- The measurement was of differential signal level, not absolute signal
>level. The reference was the HP-355 1db/step attenuator set that was
>used to generate a calibration graph of the S-meter reading/s versus real
>decibels.
>>What bandwidth did you cover?
>garden-variety SSB.
>>How did the IMD products decay? i.e. what level at say 5 KHz from f0?
>I did not measure it. I was not concerned with distant products. I
>wanted to see what the ratio (in db) of the signal level in the
>fundamental window was compared to the signal level just outside the
>window.
>- Every SSB radio and every linear amplifier generates splatter outside
>the fundamental transmitting window. A signal report of 'you are not
>splattering' is abundant bovine feces. The question is relatively, how
>much splatter? A signal report of S9 splatter is good if the
>fundamental signal is 40db higher. On the other hand, a signal report of
>S6 splatter is not good if the fundamental signal is S9 (+18db).
>{**a single receiver can be used to make the measurement by doing the
>3.6kHz offset with the RIT.}
-snip-
>>>Most people won't tell me when my zipper is down, Lars.
>>
>>Rich...
>
>Thats to bad Rich, not only for me, but maybe even in a higher degree for
>you...! ;)
I got one e-mail saying that unzipped/fly down is called 'trolling for
bimbos' in Texas.
>cheers, Lars
>Rich...
-snip-
Although I dont agree with the accuracy of your measurements on G2DAF amps
Rich, I do appreciate your sense of humour!
Whenever you go to Texas, Rich, - Good luck!! ;)
73´s de Lars
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Lars Harlin Private: lars.harlin@pocab.se
Gräftågränd 22 Hobby: sm3bdz@pobox.com
S-831 71 Östersund Work: http://www.pocab.se
Sweden
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