>
> On 23-May-10 1:56 PM, Carl wrote:
>> If the average ham simply reduced the power of his ricebox to 75-80% of
>> its
>> ratings he would pick up a 3-6dB IMD improvement at least. Then he can
>> use a
>> decent amp instead of operating in GIGO mode.
>>
>> Carl
>> KM1H
>
> This only works if the amps is tuned for max carrier power and then the
> drive is reduced so that the PEP output power is 20-25% less than the
> carrier tune up power. Otherwise if the amp is tuned for the lower
> power, there isn't much difference. Doubt it? Hook up your spectrum
> analyzer and check it.
>
> 73, Larry
>
You start by reducing the internal low level drive control so that the panel
control doesnt go beyond 80W for a 100W rig. You can fine tune by adjusting
the bias a bit more towards Class A; just enough so the heat sink temp
doesnt change.
The exercise is to drive an already clean amp with a lower IMD signal.
Perhaps you dont understand GIGO.
Ive run that way and SA measured the results in many rigs going back to the
days when when the TS-930 was new. The amp is happier also since the
LK-500ZC I bought new in 86 still has the original tubes and loafs at 1200W
instead of 1400W. The MLA-2500 on the second station also thanks me as it
also runs the original 8875's. The current HF SSB/CW exciters are modified
TS-940's which have excellent IMD.
Carl
KM1H
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|