[Boatanchors] Want to buy a pair of tested 5651WA voltage regulator tubes (new)

[Richard Knoppow]

    Doug, what is wrong that makes you think your tubes are bad? I am 
assuming they are not missing.  They very seldom go bad and you can test 
them without a tube tester. The handbook has voltage and resistance 
charts in it. if the tubes don't light look for the voltage at the 
anodes, it should be quite a bit higher than the regulated voltage. The 
handbook I have shows the older neon lamps but the voltages should be 
the same. I sent links to the handbook and the 5651 and 0G3 tubes (which 
are identical). Take your VOM and check the voltages. These tubes glow 
orange when working.
     If the tubes don't light and there is voltage there its possible 
the tubes are bad but look for the supply voltages before going on a 
search for new ones.
    They should not be rare, they are used in many power supplies, in 
many Hewlett-Packard instruments and others.
    I found both tube data sheets and the handbook for the meter via web 
searches, not difficult. I will repost links to both if you need them.
     Again, while the military handbook I found shows the earlier neon 
lamp regulators the circuit is probably identical for the 5651 tube. The 
voltages at the tube will tell you the story. The tubes will not light 
if the voltage is missing or below the strike voltage. if the tubes are 
open for some reason the voltage from anode to cathode will be quite 
high. Also, check the resistors at the anodes. In fact, there is a 
resistance chart in the book. If the meter is not working a first step 
in trouble shooting is to check the resistances. Next step is to check 
the voltages against the voltage chart. Always start with the power 
supply, if that isn't working nothing else will work.
    Again, cold cathode tubes rarely go bad so look for something else.
    Sometimes they become unstable and must be replaced but make sure 
its the tubes and not something else.
    You seem to be a tube collector so should know this stuff.

On 6/18/2024 2:36 PM, Doug Hensley wrote:
> Subject says it all.  QSL if you can supply.
> 
> 73, Doug W5JV
> 


-- 
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998