?
Stan,
?
According to Item 2 of the TX Adjustment on pg.
124, you should measure ~10dBm minimum at
CN-9 on the RF board. You should be able to connect
your SA through a DC block?across the output of the cable connected to
CN-9, or connected across the?other end of the CN-9
cable?itself.
?
Personally, I use a section of .141 rigid cable
with?an SMA female connector on one end, then I can connect my RF
millivoltmeter or when necessary, my SA.
?
Page 163 shows RX and TX stage AF and RF levels as
well...
?
73...Jordan VE6ZT
----- Original Message -----
Sent: Sunday, February 25, 2024 3:24
PM
Subject: Re: [Kenwood-Amateur-Radio]
TS-690S transmits on 6m but not on HF
Using my spectrum analyzer, I placed an RF sniffer probe near
the output connector of the of the HF amp board. I saw activity at the proper
frequency, but at a very reduced level as compared to what I saw when
transmitting on the 6 meter band with the probe near the 50 MHz output
coax.
I've looked at the HF amplifier schematic in the service manual,
and it shows what I assume are DC voltages at various points around the board.
Some points show only a single voltage, and other points show a second voltage
in parentheses. I assume that the first voltage is measured in the receive
mode, and the second voltage (if present) is measured in the transmit
mode.
I don't see any references to what HF levels I should see at the
various points in the signal chain.
I'm thinking that the low output is
due to either a failed transistor (or transistors), a problem with the level
of the RF input to the board, or a poor connection at one of the connectors,
but without knowing what the expected RF levels at the test points are, I
would just be guessing.
Any help on how to proceed from here is
appreciated!
73,
Stan N6BYU
