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-   -   High Voltage Components from microwave ovens (https://www.radiobanter.com/homebrew/23316-high-voltage-components-microwave-ovens.html)

[email protected] June 26th 04 06:21 AM

The transformer is good for 1500 to 2500 VRMS at 0.5 A or more.
I would check to see if these transformers are continuously rated,
I seem to recall they are rated for intermittent use only.


Several years ago, while driving from Kansas City to Manhattan, KS (about
130 miles) I had an interesting QSO most of the way with someone who said
his amplifier was powered by two microwave-oven transformers (two are
used because the high-voltage winding is usually connected to "ground"
internally).

--Myron, W0PBV.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

Paul Keinanen June 26th 04 10:56 AM

On Fri, 25 Jun 2004 23:28:12 -0000, (Dave Platt)
wrote:

According to a talk I saw recently, commercial television broadcasters
have moved almost exclusively to solid-state RF amplifiers for their
newer stations. No one set of transistors can provide thenecessary
power, so the amps use a large number of smaller modular amplifiers
operating in parallel - I think the basic "brick" we were shown was
capable of a couple of hundred watts. I haven't seen any ham-band
amplifiers using this modules-in-parallel approach, although I'm
sure one could be built.


In broadcasting, the station is usually operating on the same
frequency all the time, so simple Wilkinson dividers/combiners (which
are frequency specific) can be used, which effectively isolates the
modules from each other, when one module fails.

However, a ham linear amplifier is typically required to operate in
the 1.8-30 (or -54) MHz frequency range, which complicates the
divider/combiner issue.

Paul OH3LWR


Albert June 26th 04 01:18 PM

Yes, please publish the link Wm, and thanks.


On Fri, 25 Jun 2004 22:42:38 +0100, "Wim Ton"
wrote:


"Albert" wrote in message
.. .
Are old high voltage components from microwave ovens useful, or should
I chuck them out in the trash?

I have several transformers that look like they are good for quite a
few watts of power, some of the high voltage diodes and several
blowers. I've been saving them.

Can they be used for power supplies for rf transmitters? Are the
blowers any good for cooling large tubes in transmitters?

Of course you can use the diodes and the capacitors ;-)
There are some articles on th Internet about converting the transformer for
a spot welder.
A also saw an article on using the magnetron as a PLL like amplifier to put
out 1kw at 13 cm. I can forward the link if you want.

Wim







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Doug Smith W9WI June 26th 04 02:01 PM

Dave Platt wrote:
According to a talk I saw recently, commercial television broadcasters
have moved almost exclusively to solid-state RF amplifiers for their
newer stations.


I suppose this is kinda OT but tubes (usually, klystrons or various
modifications thereof) are still generally used for high power at UHF.
IIRC solid-state UHF transmitters are available up to about 30kw or so,
but larger stations require as much as 110kw to achieve the desired
effective radiated power.

Tubes do indeed seem to be a thing of the past at VHF, where powers
beyond 50kw are generally not necessary.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com


Wim Ton June 28th 04 11:48 PM

Hi, I lost the link and the newsserver did not like the 1.3 Mb pdf I
attached. Please mail me and I send it directly to you .This is my real
address as the account is spammed anyway :-( The article is not findable
with a search engine, I stumbled upon it.

Wim

"Albert" wrote in message
...
Yes, please publish the link Wm, and thanks.


On Fri, 25 Jun 2004 22:42:38 +0100, "Wim Ton"
wrote:


"Albert" wrote in message
.. .
Are old high voltage components from microwave ovens useful, or should
I chuck them out in the trash?

I have several transformers that look like they are good for quite a
few watts of power, some of the high voltage diodes and several
blowers. I've been saving them.

Can they be used for power supplies for rf transmitters? Are the
blowers any good for cooling large tubes in transmitters?

Of course you can use the diodes and the capacitors ;-)
There are some articles on th Internet about converting the transformer

for
a spot welder.
A also saw an article on using the magnetron as a PLL like amplifier to

put
out 1kw at 13 cm. I can forward the link if you want.

Wim







-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----




Wim Ton June 30th 04 09:25 PM


"Albert" wrote in message
...
Yes, please publish the link Wm, and thanks.

Use a mgnetron as an amplifier


http://www.dafh.org/gbppr/mil/herf/m..._amplifier.pdf




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