[AMPS] choice

Radiodan W7RF RFpower@radiodan.com
Tue, 4 May 1999 16:34:38 -0700



> >The Henry amplifiers using 3-500 tubes are quite mature and stable,
>
> €  To the best of my knowledge, the World Record for grid-fil. shorting
> brand-new 3-500Zs in under one day is currently shared by two 3K-A Henry
> Radio amplifiers.  Both amplifiers reportedly shorted four 3-500Zs -
> accompanied by stentorian big-bangs. .  . I attribute this feat to:
> 1.   no peak fault current limiting resistance [glitch resistor] in
> series with the high voltage positive lead.

I didn't know you were the "Guinness book" keeper of these things in
amplifiers.
Good to know........

My guess is that the amplifier lived through this disaster.
Defective tubes caused this problem, NOT the amplifier!

> 2.  maximal anode potential =s high vhf voltage gain.

Maximum rated voltage makes the tube run more efficiently (as per your own
recommendations to others)

> 3.  low ESR filter capacitor

Same oil filled transmitting type filter as used successfully and still in
service MANY years after those toy "computer caps" fail. Lots of discussion
here about how much current you can pull through them all stitched together
and equalized to get the working voltage up to a usable level. Not a problem
with Henrys method of using the proper parts for the job!

> 4.  relatively high-Q vhf "suppressors".
They work!
The proof is in performance, we don't see much evidence of damage from VHF
parasitics in reality. More "hypothetical" than actual.

> 5.  no vhf loading in the cathode to reduce vhf feedback.
> >.....

Again VHF parsitics are not a problem or we would have amplifiers returned
by the thousands.
Henry has a three year warranty, not often used. Let me preempt the retort
that the amps are heavy to return to the factory. I also mean we do not have
to regularly send in-warranty spare parts to Henry amp users either.

> >It is widely known that the Kenwood TL922 had more than it's share of
> >problems
>
> €  true.   The vhf suppressors in the TL922 appear to be rather similar
> to those in the 3K-A.

You wouldn't be inferring that the only problems with TL922s are simply the
VHF suppressors because they are similar to Henrys. Nah...I didn't think so.

Have a wonderful day!

73, Dan Magro W7RF, (President WARC 1999, member SCDXC, SCCC)
Manufacturers Rep & Distributor for HENRY RF Power Amplifiers.
www.radiodan.com <http://www.radiodan.com>     RFpower@radiodan.com
<mailto:RFpower@radiodan.com> A trip to our web site is worth the click!


>
> >...
> -  cheers Dan.
>
>
> Rich...
>
> R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
>
>


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