-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
-
The Feb 2025 Radioddity Giveaway Results are In! Click Here to see who won!
Browning Mark 3
- Thread starter Mr Clean
- Start date
IF this is the SSB/AM transmitter, V9, the 6BQ5 is the AM-only modulator. Has no SSB function. This tube is almost dead-center of the chassis deck.
V8, just to the front of V9 is a 12AU7, also AM-only. Serves as a clipper, and drives V9.
V7, a 12AX7 is just to the front of V8. This is the mike preamp tube, and the mike gain control is attached to what comes out of this tube. On early Mark III SSB radios, the mike gain controlled both AM and SSB mike gain.
On the later version, it affects ONLY the AM modulation, but not SSB.
73
V8, just to the front of V9 is a 12AU7, also AM-only. Serves as a clipper, and drives V9.
V7, a 12AX7 is just to the front of V8. This is the mike preamp tube, and the mike gain control is attached to what comes out of this tube. On early Mark III SSB radios, the mike gain controlled both AM and SSB mike gain.
On the later version, it affects ONLY the AM modulation, but not SSB.
73
Hmmmm. Didn't ask why he wanted to know which ones are the audio tubes......
If all three of them are good, and you STILL have no audio, this is the place to look next, for a burned resistor. It's supposed to have two orange bands, a red, then silver.
If this one is burned, your mode selector switch has broken down. That's the AM/USB/LSB selector switch.
Rare to find one that hasn't. One of the first results is R51 burning up. Attempts to use a larger resistor don't fix the missing audio.
It's also common to see the meter peg violently to the right when the meter switch is set to "Mod", soon as you key it, or maybe while receiving, both.
Of course, if you click it back away from "Mod" fast enough, the meter will survive. If you're too slow, "POOF", no more meter coil.
The replacement switch is expensive. And the labor to put it in won't be cheap, no matter who does it.
73
If all three of them are good, and you STILL have no audio, this is the place to look next, for a burned resistor. It's supposed to have two orange bands, a red, then silver.
If this one is burned, your mode selector switch has broken down. That's the AM/USB/LSB selector switch.
Rare to find one that hasn't. One of the first results is R51 burning up. Attempts to use a larger resistor don't fix the missing audio.
It's also common to see the meter peg violently to the right when the meter switch is set to "Mod", soon as you key it, or maybe while receiving, both.
Of course, if you click it back away from "Mod" fast enough, the meter will survive. If you're too slow, "POOF", no more meter coil.
The replacement switch is expensive. And the labor to put it in won't be cheap, no matter who does it.
73