Future Projects for BIG AM SIGNAL

[W2VW]

Peek Freens.

[K1JJ]

The same topic started six months later can produce different participants, different opinions and sometimes evolved techniques that were not available in the first thread.

I look back at some of my old threads even two years ago and realize how differently I would have done things.

Nothing stays static - especially in the technical whirl.

The alternative is to just read and reread old threads and never start a new one. There is so much info on the web, we could go through several lifetimes doing it. But there's nothing like a new thread, even a repeat, to get the blood flowing of old and new participants.   [caw mawn]

T

[KM1H]

I look back at some of my old threads even two years ago and realize how different I would have done things

.

Ditto, I usually go no further than my property lines for what I need as what isnt in the basement or attic can usually be found out in a storage trailer, old van or truck body or an outbuilding.
The best thing about old age is Im always finding something new

The odd needed part can always be found somewhere on the Internet or a visit to ESS.

[W4RFM]

A slightly newer edition of the Orr Handbook is available on line as a PDF.

http://www.tubebooks.org/Books/intro_orr_radio.pdf

I think it is the 15th edition.

[flintstone mop]

The key to using 833s successfully is proper ventilation and plenty of it, as demonstrated here.

Makes you wanna just reeeach over and tweak that big bread slicer, dunnit?

No it didn't. I'm willing to bet you have a lot more hell left in you.   

This should clean out the rest.

I don't think Steve QIX would approve of those clipleads

[ka4koe]

YIKES!

I wonder if that plywood is fire rated?

IF it is it will have a little red stamp on it that says FIRE RATED. Fire marshals don't like it when you paint over that stamp.

[KM1H]

Carl sure likes to rain on other peoples' parades...

203Z= 838 available <$75

2A3= 6B4G available  <$100 pr.

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And 203's are mostly gone to air. The 812A is a direct zero bias sub.

Carl

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Not even close. Maybe a typo? 811?

http://www.r-type.org/pdfs/812a.pdf

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WOW Carl
You are taking a beating in this thread.

But I agree about vintage special period transmitter designs. Limitations to what was available, and accepting performance for that time period. Not today's 125% pos peak TX and hi-fi audio.
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Nah, I just consider the sources and completely forgot about this early Page 1 part of the thread.

1. I dont consider $100-150 for a pair of 838's reasonable and a 203Z is not a 203.

2. Nor do I consider a pair of 6B4G's at around $100/pair reasonable either.

2. A 812A is a low mu tube as is a 203A. I dont see how anyone could call a 811A a sub.

There are many other candidates that the audiophools havent ruined yet such as the 814/VT-154 if you want pre WW2. It is also very conservatively rated at 60-65W Pd. The 803 is going up in price but also capable of a lot more power than listed due to a specific transmitter design being used to set the specs. It is really a 813 on steroids with about 20M the upper limit for a KW input.

Some Euro tubes are cheap in the US as the BC/SW TX's are being junked and NOS spares still around. Check out the TB5/1750.

Dont overlook the 4X150A/4CX250B family for audio. They deliver a lot of power even at 1000V. There are cheap Svetlana and Chinese ceramic sockets that fit the standard 1 1/8" hole and add some air holes for a quiet under chassis muffin fan.

For the late 40's look there is always the 4-65A, 4-125A, and a pair of 4D32's will get you a 250W carrier at 700V.

The Russian GU-81M is impressive looking and delivers a lot of power without air. Tubes and sockets are quite cheap at Eu hamfests.

Carl