[TMC] PTE-1

[sdaitch@ibb.gov]

Generally, they were spectrum analyzers.

The typical method of tuning the TMC SSB/ISB
transmitters was to tune as typical, peak the
grid, dip the plate, using carrier from the exiter.

When the transmitter is tuned up to the proper 
power level, using the metering systems (plate current
and power power output), the carrier level is noted on 
the spectrum analyzer display.

Then the audio is "turned on" and the audio level 
is set for the proper level, using the spectrum
analyzer to monitor audio peaks for the proper levels.
Voice/music is a little tough to set correctly, as one
might have to use their judgement for the audio peaks.

In the case of tones, such as multiple channel FDM TTY 
or similar, the peaks are adjusted downward from the
peak carrier level, using a chart, based on the number of 
tones.  In other words, the CW level could be the peak
power of the transmitter, but the average level of a 
16 channel FDM TTY signal is going to be something
on the order of 20 dB or so down from peak level, so
the instantaneous peaks do not overload the transmitter.  
I don't have the numbers with me, but 20 dB down is a 
good starting point.

No tubes, tho.

Sheldon
WA4MZZ

----- Original Message -----
From: telegrapher@att.net
Date: Wednesday, April 14, 2004 6:09 pm
Subject: [TMC] PTE-1

> I've not seen one of the portable analyzers that rolled around on
> casters that TMC made for adjusting transmitters but i wonder just 
> whatkind of display the tuner uppers were looking for?
> 
> What were they looking for on the signal?  Some sort of trace that 
> wouldindicate linearity or was it just an expensive toy to look at 
> an RF
> envelope whether modulated with audio or cw/RTTY tones.  
> 
> Not having one of them, boy would that be fun to have around, 
> can/couldyou not get the same results with a regular O'scope 
> provided you know
> what your looking for and have it attached at the appropriate place?
> 
> Anyone got any extra 4CX350A tubes laying around?  New hopefully.
> 
> Any other TMC toys?  
> 
> I get excellent audio reports from my GPE-1 and Pal 500 configuration
> using a D-104 mic.  Only one other station that i've heard running TMC
> gear out here in the west.  Like to find some more of it.
> 
> Larry
> W0OGH
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