At 12:04 AM 1/19/97 +0100, you
snip.....
>After some guessing and hesitation the selection came to the QRO (I
thought it is a starting company and they will try hard, I also after a lot
of experience do trust to the Russian RF tubes) Here is what happened:
>
>1.it was ordered in august, promised to deliver in october, delivered in
january. (3 pcs)
>2.After less then 3 hours of operation ALL !!!!! the three QROs died.
snip.....
>
>I gave to Mr. Conin some lectures of basic theoretical electronics
concerning design of simple and primitive rectifiers and, he promised to
compensate for those lessons and my loss of time ... by sending me a pair a
spare tubes and a pair of - as a matter of fact very good - vacuum relays
he uses. You guess do I have the tubes and relays from him ?
>
>This is not an advice what to buy. It is just an advice what "not" to buy
if you are not a technical type or if you do not like the shipping
companies or if you own ICOM or KENWOOD or YAESU TRX.
>
Many thanks for speaking out, Jiri. There is nothing but silence on this side
of the pond from QRO owners. I have heard several horror stories, but second
or third-hand. Never have I heard anyone bragging about any QRO products or
service after the sale. I met Mr. Conin at Ham-Com in 1996, but he did not
show up this year. I think his training and background are in real estate.
The loading cap in the pi net is lacking in capacitance, as you found out.
The scheme of putting a 4:1 unun transformer in the output of the pi network
to save the addition of a couple of door knob caps apparently has backfired.
It appears that you are 300-400 pf short on 40m and at least 1000 pf short on
160m.(For those of you that haven't looked, the QRO amps use a simple pi
network on all models.)
I hope by your relating your experiences here on the reflector that it will
bring all the victims out of the closet and shed some more light on the
subject.
(((73)))
Phil, K5PC
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