[Kenwood] TS-570S(G)

[Gary Peach]

>
>  Evidently, Kenwood made many models with noise blankers that do
> little, if anything.
>  The ones in my TS140S don't do much that I can notice... (it has two of
> them).
>  Wayne.  <|:^)>

The present R-5000 that I am using the noise blankers have never worked.
from new :(
The noise blanker circuitry is in the 455 kHz IF and from the manual seems
quite clever.

Part of the blanker was designed specifically with the 'Woodpecker' in mind.
As that seldom if ever exists now, I have no opportunity to test that part
of the circuit.

However I am plagued by an arcing thermostat so some work on the other
section to make it functional would help.

Noise blanker pot set at Minimum
  (VR5-2 on Switch Unit X41-3000-001 (B/8))
Mode USB
Input 14.100 MHz at a level of 10 dB microvolt
The adjustment is L11, 13, 14 on the IF unit
The DC Voltage at TP2 is adjusted for minimum
    The specification level is less than 2.9 Volts.

I have not yet attempted this adjustment, has any one else?

Is there a better method using a noise source?

The noise detector is D3 on unit X48-3000-00
Noise blanker AGC comes from the collector of Q14 on that board
The other active components involved are Q16, Q17, Q18, Q25.

73 de Gary7SLL