32v2 solid state LV and HV

[W3RSW]

Plus, if something might crap out in my shack, I want to know about it and fix it.

I don't know why, but that's pretty funny on several fronts (or backs).

Given time, everything will.

I guess we are fortunate in having the smarts to pick our battles.

[N2DTS]

Well, I have to say, I have had a lot of equipment in the shack over the last 35 years or so, and cant think of anything that crapped out.
I bought some stuff that did not work, or did not work right when I got it, but cant think of anything other than the 30k-1 that crapped out, and THAT crapped out while doing full power frequency response tests.
I got down to 20 hz and blew out the mod transformer (live and learn). That was the only transformer I EVER had fail.
I think even the haywire DX100 I had generaly worked.

The R390a broke about 4 clamps early in its life, but after that seemed to just work, for the last 15 years I had it, it never came out of the rack. After about 20 years of heavy use, it still had all the original tubes in it when I sold it.

I never was one to baby anything I own, cars, motorcycles and radios got beat on and generaly gave good service.
I remember the abuse the G76 took, transmitting into antenna's with a high swr (at pre hamfest camping trips), running it well over the normal plate voltage, out in the rain sometimes, thrown around in the car, and it just always worked.

I never had much Johnson gear, only a viking 2 which I scrapped for parts because it did not have a vfo...so maybe that is why I was lucky.
The NC300 and 303 never gave trouble, nor did the sx17, or Scott slrm, the 75A4 and KWS-1 worked fine for many years, the sx101 never gave problems, nor did any of the Drake stuff.
The 75s1, kwm2-a were trouble free, the milti elmac worked fine, the Globe scout worked as well as it could.
The various heathkit rigs like the hw101, DX60 and so on always worked like they were supposed to.

I never worried about line voltage, most stuff had solid stated high voltage supplies, and cant think of anything that needed a tube replaced if they were good when I got it.

I suppose stuff is getting older and older (like us), but rather than baby it, I would strap it and fix the crapouts.
That is partly why I got rid of almost everything other than the homebrew, you can BUILD something to be reliable at full strap.
I was able to put a 3rd tube in the 4D32 rig and still be over built.
The 32V3 with the solid state diodes runs the iron cool, just above room temp, but I think they get hot with all the rectifier filiment power on them.

So having said all that, I am sure to have something crap out now!

The 2x813 rig is WAY overdue, its not been opened for 20 years!
If it craps out, maybe I can put in a third 813.....

Brett







 

[w1vtp]

I looked into one of those rectifier replacements and decided (after pulling one apart) that it would be easier and better to "roll my own."  If the SS rectifier mod is done a suggestion: take the unused 5 volt fil winding and use it as a bucking winding in the primary to cool things down due to today's higher line voltages.

Here's what I did.  The last page is not germaine to our topic but it's the TX / RX SS switching schematic.

Al

[Jim KF2SY]

Well, I have to say, I have had a lot of equipment in the shack over the last 35 years or so, and cant think of anything that crapped out.
I bought some stuff that did not work, or did not work right when I got it, but cant think of anything other than the 30k-1 that crapped out, and THAT crapped out while doing full power frequency response tests.
I got down to 20 hz and blew out the mod transformer (live and learn). That was the only transformer I EVER had fail.
I think even the haywire DX100 I had generaly worked.

The R390a broke about 4 clamps early in its life, but after that seemed to just work, for the last 15 years I had it, it never came out of the rack. After about 20 years of heavy use, it still had all the original tubes in it when I sold it.

I never was one to baby anything I own, cars, motorcycles and radios got beat on and generaly gave good service.
I remember the abuse the G76 took, transmitting into antenna's with a high swr (at pre hamfest camping trips), running it well over the normal plate voltage, out in the rain sometimes, thrown around in the car, and it just always worked.

I never had much Johnson gear, only a viking 2 which I scrapped for parts because it did not have a vfo...so maybe that is why I was lucky.
The NC300 and 303 never gave trouble, nor did the sx17, or Scott slrm, the 75A4 and KWS-1 worked fine for many years, the sx101 never gave problems, nor did any of the Drake stuff.
The 75s1, kwm2-a were trouble free, the milti elmac worked fine, the Globe scout worked as well as it could.
The various heathkit rigs like the hw101, DX60 and so on always worked like they were supposed to.

I never worried about line voltage, most stuff had solid stated high voltage supplies, and cant think of anything that needed a tube replaced if they were good when I got it.

I suppose stuff is getting older and older (like us), but rather than baby it, I would strap it and fix the crapouts.
That is partly why I got rid of almost everything other than the homebrew, you can BUILD something to be reliable at full strap.
I was able to put a 3rd tube in the 4D32 rig and still be over built.
The 32V3 with the solid state diodes runs the iron cool, just above room temp, but I think they get hot with all the rectifier filiment power on them.

So having said all that, I am sure to have something crap out now!

The 2x813 rig is WAY overdue, its not been opened for 20 years!
If it craps out, maybe I can put in a third 813.....

Brett







 

You just sealed the deal, ,,,,,last time I bragged about how my TV was still chuugging along after 15+ years
it crapped the next day.  I'm not kidding, my wife still loves to tell the story.

You just upset Murphy's Laws, the Radio Gods, gremlins, etc.  They will come calling.

 

[w1vtp]

After reading the posts on this thread I see there is a bit of talk about crapouts.  Here’s my worry about my EFJ Courier:  every once in a while I get a snap when I turn  on the HV.  One time (before I had the whole shack rewired with up to date 20a 120 v wiring) I turned on the HV and the Courier snapped and I tripped a rather old 15 amp breaker downstairs.  A few times when I turn on the HV I get a snap and see a little flash around where the 3B28’s are located but that’s it.  One time I turned on the HV I blew a 10 amp fuse in the Courier – really nuked the fuse.  I now use an 8 amp fuse and say a little prayer each time I turn on the beastie.  Over all the old girl puts out what she should in fine style but that occasional snap is unnerving.  I was told the EFJ Couriers were known for high inrush current
Al

[WQ9E]

Al,

A perfect case for an inrush limiter.  They really are cheap insurance and help prevent damage and nuisance fuse blowing.  I would also check for dust/carbon tracking around the 3B28 sockets.

That is an attractive little amplifier.

Rodger WQ9E

[The Slab Bacon]

Just my $.02 worth..................

SS versus tube rectumfryers have somewhat matching advantages and disadvantages.

Like Gito had mentioned you have the inrush issue. With vacuum tube rectifiers, you have a natural "ramp up" effect that eliminates hard starts and heavy inrushes.
this is due to the increasing current flow as the filament heats up. No inrush suppressors are usually needed.

However you now have the HV on the rectifier filament winding. this is now another place where a possible insulation breakdown can occur.

The vacuum rectifiers (5u4s, 5r4s, etc) will usually fry and burn out before taking out the transfoma if you have a short or heavy leakage downstream. (shorted or dying filter caps, etc) somewhat acting like a fuse and saving the transformer.

SS rectifiers do give much stiffer regulation, and more output voltage and less heat.
Today's diodes usually last forever but sometimes require compensation circuits as well.

MV rectifiers just plain suck! Except for my Valiant that uses them for their current capacity and not their voltage capacity, they will just about always flash over on you if you dont let them warm up enough. But...........they do look kool!!!

I dont always feel that the choice is that cut and dry (but I do tend to favor SS)
You have to decide which is right for your application.

                                                   the Slab Bacon

 

[w1vtp]

<snip>...
MV rectifiers just plain suck! Except for my Valiant that uses them for their current capacity and not their voltage capacity, they will just about always flash over on you if you dont let them warm up enough. But...........they do look kool!!!

I dont always feel that the choice is that cut and dry (but I do tend to favor SS)
You have to decide which is right for your application.

                                                   the Slab Bacon

 

Yeah, but you gotta love those MV’s in the mudlator PS.  That recent thread on the 1 KW AF amp playing the fugue has lit a fire under me to go to MV’s   I plan to put a timer on the HV anyway.
Al