Discussion in 'Amateur Radio Amplifiers' started by KG4RSF, Mar 18, 2018.
thx roger. I m going to plug in later today and and give you definitive answer. thx again
No, it's not a shunt. That's impossible.
A shunt increases the range of an ammeter or milliammeter (or microammeter), allowing the meter to work with higher currents.
When you create a voltmeter, you use a resistor in series with the meter (not in parallel with it) to convert the reading from current to voltage. The question in this case was a "voltmeter" reading. A voltmeter doesn't use a shunt, it uses a series resistance normally called a "multiplier."
The multiplier is 3M on the 2100Z with 5.1k across the meter. I saw 1.5M multiplier with no external R across the meter on the 2100B scheme.
In both cases, the meter is fed halfway up the capacitor stack (1200v nominal).
This looks kind of strange. R4 ?
Is the tap touching the metal case ?
I noticed the switch from operated to stand by is a double switch. the one side of it works ok. the other side is always closed. could that be the problem .. having trouble uploading a pic
no not touching
Hard to diagnose or debug remotely.
But if the amp was on my bench, I'd know what the problem was in a few minutes.
I think this reinforces my feeling about "never buy anything you didn't see working." That's why in 53 years I've never bought a rig via the internet or any of its many applications...whatever is there is also available locally, so I can go try it out.
It is a lot different when you work on electronics all of your life to make a living.
Speedy troubleshooting makes more money.
I like to buying virgin equipment that don't work then fix it.
To buy something from someone that thought they could fix it can be hard, Because you may have to unscrew it up first.
If it is not disconnected, You may be measuring the pilot lamp and transformer winding.
Is your meter on RX1 ? The switch contacts would need to be shorted to ground, To make it key.
No . . . even if it was shorted inside the switch, the Amp would not go to Transmit mode (ie the Relay activate) until you ALSO short the RLY terminal (on the back) to ground - normally done by the relay in your Transceiver, when you go to Transmit.
You need to tell me what the Standing Current value is, on the Ic meter, as this will be a big clue as to the fault !!