HRO50 - 1 S Meter

[kd1nw]

Hi All,

I'm having an issue with the s meter on a 50-1 where it jumps up about 3 s units, i think when the VR tube fires. I can't watch them both at the same time. The meter itself is fine, properly deflects to zero and reads sig strength okay etc. Radio is recapped but it was doing this before any work was done. I'll keep looking into it but wanted to ask here in case someone has experienced this issue.

Thanks 73
Kevin KD1NW

[WQ9E]

Kevin,

Is the gas in the VR tube not staying ionized all of the time the receiver is on? 

If not, whatever is causing that is the underlying issue for your S meter and it is likely that something is putting a heavy intermittent load on the B+ supply either on the regulated or unregulated side of the VR tube.  It could also be the current limiting resistor feeding the VR tube but I suspect something is intermittently heavily loading the entire B+ bus causing the voltage to drop and you need to find that before it damages the power supply.

Rodger WQ9E 

[kd1nw]

Thanks Rodger, it is staying lit and I checked that resistor. It has drifted from 5k to about 6k. Okay on the power supply I'll be careful and try not to power it up too much while i track it down. Thanks