|[AMRadio] TS430 as VFO on a KNIGHT T60|
John Coleman ARS WA5BXO
wa5bxo2006 at pctechref.com
Sun Oct 15 11:44:50 EDT 2006
For using the Kenwood TS430 as a VFO to go into the Knight T60, yes
you can use the AM mode with audio gain turned down on the TS430 and put a
dummy load on the TS430. I don't remember what voltage is required at the
T60 input. My guess would be 5 - 10 volts PTP but it has been to long ago.
If the TS 430 is attached to dummy load and the input to the T60 then you
will need about 1/4 watt on the dummy load to get the 10 volts PTP at the
T60 input. A 2 watt 50 Ohm resistor across the input of the T60 should
serve as the dummy load fine. The "Transverter" output with a step up XFMR
or tuned network is a better idea.
However, the best idea is to use the AM mode of the TS830 at about
20 to 25 watts carrier output to the antenna and forget the T60, except for
a nostalgic piece. I used a T60 as a novice and as a general class back in
1962 - 1964. It was great at the time. The controlled carrier modulation
was barely acceptable so I built the external modulator using a pair of
807s. That made a tremendous difference. The output of the T60 in CW
mode is only about 35 - 40 watts MAX and in AM mode is about or less than 10
watts carrier with no modulation and full controlled carrier type modulation
the PEP = 35 - 40 watts. If you build and use an external plate modulator
for the T60 and run the T60 at full load in CW mode modulating it to 100%
with the external modulator the BEST output you can obtain will be a 35 to
40 watt carrier with PEP = 160 Watts. The TS430 will only be about 2 DB
below that when the carrier level is set at 25 Watt carrier output you will
get 100 Watt PEP output when modulated. The TS430 has excellent AM with
very nice modulation characteristics. The TS430 will be narrower when
compared to the T60 for 3 KHz modulation because of its great linearity.
The ALC will provide a limit for over driving the RF stages. Even if you
reduce the carrier to 10 Watts and produce 100 watts PEP with modulation, it
will be narrow because it will produce DSB energy without respect to the
carrier (balance modulator operation) therefore you will not see clipping of
the carrier as you might with full high level modulation.
As for the T60, I'm not saying "don't do it". You will want to make
your on observations for the experience. But, the TS430, when operated
properly on AM, will get you better signal and audio reports and keep your
band neighbors friendly.
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