Not so; QRO had the HF-1000 and HF-2000 with 1x and 2x 3-500z tubes.
I owned both back in my serious contesting days.
In fact they still sell the HF-2000.
It is currently my favorite amp on the market.
See: http://www.qrotec.com/
The first amp shown uses 2x 3-500z.
They have always had this amp. Discontinued the HF-1000 because the AL-80x
made life too hard for them. Couldn't compete on price. I owned an AL-80A
at the same time I had the pair of QROs. Simply no comparison in build
quality, though for the price, I think the AL-80B is now the best amp going.
BUT, you have to manage your timing with it. Its open-frame T/R relay is s
l o w.
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Mike
Schatzberg
Sent: Thursday, April 02, 2015 10:56 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Centaur Tubes odd ones in parallel
I never use tetrodes myself and that is what QRO uses.
Commander may have one of the best RF decks in the business. But their
control board is in need of help generally particularly their switching. I
have modified many units over the years.
73,
Mike
W2AJI
Sent from my iPhone
> On Apr 2, 2015, at 2:06 PM, Rick - DJ0IP / NJ0IP <Rick@DJ0IP.de> wrote:
>
> Mike, I agree with you.
> Far too many people talk only theory here, without actually "doing".
> I generally only write about things I have done myself.
>
> I was surprised to hear you had to modify the Commander.
> I thought they were pretty good amps by design.
> Very similar to my old QRO Technologies amps.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Mike
> Schatzberg
> Sent: Thursday, April 02, 2015 6:13 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Centaur Tubes odd ones in parallel
>
> Actually, I tested many of his concepts on my SB 220 which I built
> around
> 1967 or so. I do not ascribe to them all. His theory on VHF parasitic
> oscillation has remained a topic which is still controversial and
> debated to this day.
>
> I did discovered something of interest to perhaps only myself when I
> read last night his circuit improvements compendium on the SB 220. He
> had changed the wattage of his grid equalization resisters to 1/2 watt
> and added some dissipation protection as well.
>
> I wrote to Mr. Measures years ago, regarding his grid fuse concept,
> which he advocates for additional tube protection. I told him that the
> original wattage he used, 1/4 watt I think, was really too low. I also
> told him that I generally thought that resisters make poor fuses even
> if they are flameproof.
>
> I recommended that the value be changed to a 1/2 watt, and forget the
> grid fuse concept and just go with RF negative feedback and grid
> equalization which I had decided to use.
>
> Well, last night that is what I found in his circuit description.
> While he still talks about grid fuses, they will not open without
> being seriously over driven.
>
> My SB 220 was a great test bed for lots of experiments. Many of the
> concepts were so easy to apply and evaluate. My own QSK systems that I
> use today on many ceramic triode conversions were adopted from my
> Heathkit test bed. I have modified many models of Alpha and Commander
> amplifiers which are in use in many places today.
>
> As they say, one well designed experiment is worth a hundred expert
> opinions. I generally don't offer opinion but rather test results.
>
> Sorry for the bandwidth. I know the moderator will be tolerate however.
>
> 73 and Happy DXing,
>
> Mike
> W2AJI
> Owner Ten Tec Reflector
> Owner Orion 565/566 Reflector
> Owner 1000MP Reflector
>
>
> Sent from my iPhone
>
>> On Apr 2, 2015, at 9:07 AM, Rick - DJ0IP / NJ0IP <Rick@DJ0IP.de> wrote:
>>
>> Hi Tony,
>>
>> It's W2AJI.
>> He pointed out work that Rich Measures had done on this topic.
>> Specifically it was, "High Speed Switching / QSK for the TL-922 and
>> SB-220 With Circuit Improvements for the TL-922"
>> Here: http://www.somis.org/QSK922.html
>>
>> The topic was using non-matched tubes in a multi-tube linear amp.
>> Scroll down a ways until the paragraph on ANODE AND GRID GLITCH
> PROTECTION.
>>
>> 73 - Rick, DJ0IP
>> (Nr. Frankfurt am Main)
>>
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Tony
>> Sent: Thursday, April 02, 2015 4:51 PM
>> To: Rick - DJ0IP / NJ0IP
>> Subject: Re: [TenTec] Centaur Tubes odd ones in parallel
>>
>> Rick ,
>> Who's this Mike? Does he have a website?
>> 73, Tony VE3DWI.
>>
>> Sent from my BlackBerry 10 smartphone on the Bell network.
>> Original Message
>> From: Rick - DJ0IP / NJ0IP
>> Sent: Thursday, April 2, 2015 04:08
>> To: 'Discussion of Ten-Tec Equipment'
>> Reply To: Discussion of Ten-Tec Equipment
>> Subject: Re: [TenTec] Centaur Tubes odd ones in parallel
>>
>> Well done, Wade!
>> As Mike showed us, it indeed can be done that way.
>>
>> 73 - Rick, DJ0IP
>> (Nr. Frankfurt am Main)
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|