UnidenWashington variable power

[BAGEBOY]

I I have a unidenWashington the vr 6 was removed and ran to the rf gain control. It doesn't vary.i checked and they is no voltage ant the pot or the board where the wires are connected. So I am not seeing the 8v.

 

[nomadradio]

Does this mean the carrier is always the same? How much?

Or is there just no AM carrier at all?

Sound as if you have no carrier power.

One of the three pads on the pc board where the trimpot was removed should have 8 Volts DC while transmitting. One foil trace to that pin of the old trimpot will lead towards the front of the radio. Follow this trace and see if any jumper wires were removed. Somewhere at the other end of that trace and jumper wires you should have 8 Volts.

Does this radio transmit on sideband? You didn't say.

73

 

[BAGEBOY]

Yes it transmits on ssb.the Carrier is the same.all the time 6watts. Actually I mis type I am seeing 8volts ..I seem to be missing a ground. My reasons is I am seeing 8volts on all 3 tabs where the trim pot was remove

 

[nomadradio]

Sure sound like either the counterclockwise lug of the control is not connected to ground, or the control itself has failed internally. We used to see this a lot decades ago. The audio voltage feeding into the wiper of the pot will create excess current in the resistance element when you turn it down really low.

We learned to use a diode between the wiper of the carrier control and the modulator circuit. This isolates the pot's wiper terminal from high audio voltages.

Never have posted the hookup we use for this. Probably ought to one of these days.

73

 

[BAGEBOY]

Thanks it was actually a dry joint causing me too loose groind

 

[nomadradio]

Hey, you got it working! That's what matters.

73

 

[BAGEBOY]

Only challenge I have is I can't get it go lower than2 watts dead key .I jumper the resistor I change the pot but still no change...any ideas how to lower my deadkeyba bit more maybe around 1 wattd

 

[nomadradio]

Does it have a 220-ohm 1 Watt resistor alongside the AM modulator transistor TR34?

Try removing the resistor.

73

 

[BAGEBOY]

Does it have a 220-ohm 1 Watt resistor alongside the AM modulator transistor TR34?

Try removing the resistor.

73

I have sent you a pic to confirm

 

[nomadradio]

Yeah, that resistor. Red/red/brown.

73