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[VE7RF]

Pole Type Transformer Alternative Plate Transformer.  Note, if you have one of these custom wound, get them to wind the 240 vac winding on 1st...then the HV winding on top of that.  The 240 vac winding does not require a CT.  You can also get them to provide taps on both the pri + sec windings.  Have both windings wound with copper.  ( I have seen the 240 vac winding done with aluminum tape, and don't recommend it, since Al only conducts 60% as good as Cu).  Typ you can get them from 3.5 kva and higher.

https://www.youtube.com/watch?v=DG1RKoZ6knI

[W7CXC]

Back in the day they were referred to as "Pole Pigs". 

[VE7RF]

This is where everyone has been buying pole pigs from, for the last 20 years.  Superb service..and reasonable prices..and typ free shipping too.

https://t-r.com/?utm_source=Google&utm_medium=cpc&utm_campaign=purchasing&gclid=EAIaIQobChMImf3c6s_c_AIVCw7nCh0PBQhBEAAYASAAEgJE4_D_BwE

[KM4AH]

How do you make these work without a really stout variac ?

Bucking transformer ?

[VE7RF]

How do you make these work without a really stout variac ?

Bucking transformer ?

You order them with the EXACT secondary voltage(S) u want.  No variac or bucking xfmr required.

[VE7RF]

How do you make these work without a really stout variac ?

Bucking transformer ?

You order them with the EXACT secondary voltage(S) u want.  No variac or bucking xfmr required.

You order them with the EXACT secondary voltage(S) u want.  No variac or bucking xfmr required. Ditto with the primary taps. My dahl xfmr has +10, 0, -10V taps at one end...then a 208 and 240 vac tap at the other end.  Done that way so you can then get 6 x  pri taps at .... 198-208-218...and also 230-240-250...using a total of JUST 5 pri taps.

If you did it the conventional way, it would be 0-198-208-218-230-240-250... 7 taps in total.  Those taps are huge things, consisting of 1" wide, and thick buss bar, terminating on the underside of the 1/4" thick red micarta sheet, on a 3/8" brass bolt. Bolt heads on the bottom, and brass nuts on top.  Dahl's method eliminates 2 x taps.

IF I had to do it again, I would spec +/- 5 vac taps...then at the other end, taps at 225 and 240 vac.   Then the 6 x combo's would be 220-225-230-235-240-245.   What I need right now is a 225 pri tap.  I only have a choice of 218 or 230, so used the 230 tap.

On pole pigs u can order em with +/- 5 or 10 vac..... or +/- 5% or 10% primary taps. 

On my dahl secondary side, it's tapped at 0-2300-3900- 4800-5200.  By using the  2300 + 5200 tap, the difference between em is now 2900 vac.    By using the 2300 + 4800 taps, the difference between em is now 2500 vac.  So I have
2300,2500,2900, 3900, 4800, 5200 vac.  6 x combo's in all, using just  the 4 x taps.

[KM4AH]

I have two primaries and two secondaries on my EPD.

The question was pertaining to pole pigs.

Lowest secondary, if you are looking backwards from it's intended purpose, that I saw was 7200. And, then you have to rectify that.



Well, I take that back they do have a 4160 several pages in that would be about right.

[VE7RF]

I have two primaries and two secondaries on my EPD.

The question was pertaining to pole pigs.

Lowest secondary, if you are looking backwards from it's intended purpose, that I saw was 7200. And, then you have to rectify that.




Well, I take that back they do have a 4160 several pages in that would be about right.

7200 vac pigs come out to 10,180 vdc no load, then subtract the 20-35 vdc drop from the diodes, and drop across the 50 ohm glitch resistor...then the V drop from the street, etc, etc.

You can get pole pigs in 4160/4800/7200/12,500/14,400 vac.

In this case, they are bought brand new, and custom wound to your spec. 

Most 4800 vac pigs also have a 4160 inboard tap as well.

These folks ship all over the country, so the shipping is usually free.  If you buy a used pig, then it has to be crated up, and shipping charges.

When I got my 4800, 10 kva pig, (removed from oil),  previous ham owner had sliced off the 4160 taps, like inside a bit.
  No way could I tap off the sliced off stubs.  4800 is not enough for a 3x6..and too much for a 3x3.   So sold the 6700 vdc supply to a local engineer ham buddy, who uses it on his  HB  YC-156.

Got pissed off, and bought the 253 lb dahl...for $1410.00 brand new, wound to my specs...(+ $225 for shipping).
 Ok, now I have a xfmr, that will run anything...and everything.

[K7LZR]

Geez and here I thought that I was kickin' a$$ with 120+ watts from my old Icom .

[VE7RF]

Geez and here I thought that I was kickin' a$$ with 120+ watts from my old Icom .

Most folks find out real fast like....that's it's just as easy to build a big amp as a smaller one.
I can build a pretty big amp for  $7k to $10k.

[KB8VUL]

Geez and here I thought that I was kickin' a$$ with 120+ watts from my old Icom .

Most folks find out real fast like....that's it's just as easy to build a big amp as a smaller one.
I can build a pretty big amp for  $7k to $10k.

Yes, if you are willing to not cheap out and spend the money for the vacuum caps and relays.  And the other part of it is you get away from tubes that cost nearly as much as a new amplifier to replace when they go bad.

I know that there are MANY here that will raise hell that an amplifier that is ABLE to exceed 1500 watts by a factor of 3 or more has no business on the bands.  But to that I will say this.  If you build it to commercial broadcast specs, and run it at legal limit, even with a 'weak' tube it will outlive you.  And will take what a 'ham' amplifier would consider significant abuse as just loafing along.  You can't take ANYTHING that Ameritron offers and run it at 50% rated output for more than maybe 2 hours.  An amp built to commercial standards will run at 100% of its rated power with a 100% duty cycle for MONTHS, because it's designed to.  And I am not picking on Ameritron specifically.  You would be hard pressed to find ANY amp that is marketed to the ham community that would stand up to CCS levels of operation.  And the ones that will are really expensive. 

What an amplifier is ABLE to do, within reason, has little to do with how it's operated.  IF the operator doesn't run it past the power levels the FCC or what ever governing body that regulates you in whatever country you are in then you aren't gonna get in trouble.  Now this of course works to a point.  No one in their right mind is gonna build an amp with a 4CX15000 or 20000 and run it at 1500 watts.  The filament circuit power draw would exceed the total current draw of an amp with a 4cx3000, which of course will run out at 5KW all day long for months.  Now there are guys in other countries that don't have the limitations that American ham's have when it comes to power output.  And I believe the MARS operators are able to far exceed the 1500 watts that the amateurs are limited to, but I don't know that for sure. 
But if they are NOT limited to 1500 watts, a box with a 3000 or a 6000 tube in it that would put them at 10KW or whatever their limit was and still run more or less efficiently at 1500 watts wouldn't be a horrible thing. 

Are there hams that would run 10KW or more on the bands?  Sure.  But there are guys that get on, cuss and swear, cause harmful interference on purpose and all other sorts of things that they aren't suppose to be doing. 
And to that end, would you rather have someone running a clean 10KW that was maintaining his bandwidth and not 'splattering' all over the band, or some clown driving the hell out of a 3-500 that is blowing out for 5Kc in both directions off his center because when he drives it WAY too hard it will do a KW or close?  I am gonna go with the dude with the big box every time personally.