LOOKING FOR A 5U4G SOLID STATE SUBSTITUTE

[K6JJR]

I'm looking to replace a 5U4G rectifier in a reciever with a solid state unit. Any suggestions would be welcome. 73 de Mark

[K9STH]

Take an old octal tube base and solder in 2 1N4007 diodes in series for each half. Connect the cathode ends of these to pin 2. Connect one anode end to pin 4 and one anode pin to pin 6. Most equipment take the rectified B+ from pin 2. If, for some reason, your unit takes the rectified B+ from pin 8 then move the cathodes to pin 8.

Total cost, less than 12 cents! At least for me, I pay 2.7 cents each for 1N4007 diodes.

If the voltage is too high, put a 39 ohm, 5 watt resistor, in series between the cathode leads and pin 2 (or pin 8).

Glen, K9STH

[KR4HV]

I'm looking to replace a 5U4G rectifier in a reciever with a solid state unit. Any suggestions would be welcome. 73 de Mark

Look At the Antique electronic Supply site. They have them if you would rather buy than build.

KR4Hv

[K6JJR]

Thanks! I was thinking of building one..looks like two diodes in a bottle!

[KE3WD]

Solid state silicon rectifiers can make RF hash when switching.

Not a problem to filter out, but a good idea to do so, especially in cases of receivers.

Simply place a .01 to .1 uF disk capacitor of high enough voltage rating across each rectifier.

Some get away with placing one .01 to .1 cap across the output or at the electrolytic's poles, as well.


73

[K9STH]

"Modern" silicon rectifiers, like the 1N4007, don't have problems with r.f. "hash" like the old ones (i.e. 1960s) sometimes did.

I use 1N4007 and the heavier 1N5408 diodes all over the place and don't have any problems at all with "hash", etc.

Glen, K9STH

[KA4DPO]

Heck yes, modern diodes switch about 100 times faster than the old Germanium or silicon diodes from years ago. Besides, anything that used a 5U4 more than likely has a B+ filter circuit anyway.

[KE3WD]

I seeand repair daily lots of designs newer than that and they still incorporate the small value caps for that very reason.

If you don't want to use 'em, don't use 'em.

Small value snubbers can be overkill or may be needed in certain cases, my viewpoint is that they are cheap enough to go ahead and incorporate in the first place and not have to be concerned with crossing that bridge (no pun intended) someday.

73

[WA2ROC]

By my calculations, just about all solid state diodes (1N4007's included) switch at the AC frequency imposed upon them.

In this case it's 120 HZ, if used in a full wave rectifier circuit.

[K6JJR]

The reciever is a Hammarlund HQ-160 thats on for hours at a time, I want to cut the power drain a bit. The 5U4 tube isnt really necessary these days. Thanks all!