I am currently using a Drake L-4B and am very happy with its reliability and
compact dimensions (the PS is packaged separately and sits on the floor in
back of the equipment table). However, the L-4B was not designed to operate
on 160, 17, and 12 meters.

I have run across two companies with almost identical equipment - QRO
Technologies and Command Technologies. I have been told that the companies
at one time were one and the same. Anyway, both companies make similar
amplifiers
QRO HF-2500DX http://www.qrotec.com/index1.html

Command HF-2500 http://www.command1.com/hf2500.asp

The outside dimensions and weights are slightly different. Does anyone have
any comments on these two amplifiers? I am especially interested in quality
of components and construction along with ruggedness. Factory support is
also an important factor. Finally, I have noticed that QRO Technologies must
have sold so much equipment prior to Xmas that they have gone South until
1-Apr-07. See http://www.qrotec.com/

Any comments or advice will be greatly appreciated.

John, N9JG

Since my original posting I have learned that the Commander HF-2500 uses
Eimac 3CX800A7 triodes, whereas the QRO HF-2500DX uses Svetlana
4CX800A/GU746 tetrodes. Some sources have stated that the IMD figures for
the Eimac triode in a grounded-grid configuration are better than the
Svetlana GU746 tetrode in grounded cathode grid-driven mode.

I have owned a QRO HF-2500DX since 1997. I have never owned a
Command, but know many who do.

The QRO uses Russian GU74b/4cx800a tetrodes, whereas the Command uses
3cx800a7 triodes. The Russian tetrodes are Russian mil spec, and have
been in good supply at extremely low prices over the last 5-10 years
(though they seem to have gone up a bit lately) whereas the Command's
triodes are still pretty pricey. My impression is that the money
saved on the tubes has gone into a more robust power supply and band
switch in the QRO.

If I had it to do all over again, I would again go QRO.

Ray K1XV

How do you prevent getting a hernia when you lift the amplifier onto the
shelf above the desk?

X-rated Vermonter wrote in message
...
I have owned a QRO HF-2500DX since 1997. I have never owned a
Command, but know many who do.

The QRO uses Russian GU74b/4cx800a tetrodes, whereas the Command uses
3cx800a7 triodes. The Russian tetrodes are Russian mil spec, and have
been in good supply at extremely low prices over the last 5-10 years
(though they seem to have gone up a bit lately) whereas the Command's
triodes are still pretty pricey. My impression is that the money
saved on the tubes has gone into a more robust power supply and band
switch in the QRO.

If I had it to do all over again, I would again go QRO.

Ray K1XV

On Mon, 18 Dec 2006 17:32:47 GMT, "John, N9JG"
wrote:

How do you prevent getting a hernia when you lift the amplifier onto the
shelf above the desk?

+++++++
It stays on the desk. If you want a lot of transformer, the result is
a lot of weight. I might add that, while the tune up process is a
little different, this amplifier has highly repeatable tune settings,
so you just keep a little cheat sheet to tell you the tune and load
positions for each band.

Seriously, thank you for your comments. I am not sure how soon I will move
on getting an amplifier like this, but right now the HF-2000DX is at the top
of my list. This amplifier got very good reviews in eHam.net.

X-rated Vermonter wrote in message
...
On Mon, 18 Dec 2006 17:32:47 GMT, "John, N9JG"
wrote:

How do you prevent getting a hernia when you lift the amplifier onto the
shelf above the desk?

+++++++
It stays on the desk. If you want a lot of transformer, the result is
a lot of weight. I might add that, while the tune up process is a
little different, this amplifier has highly repeatable tune settings,
so you just keep a little cheat sheet to tell you the tune and load
positions for each band.

"John, N9JG" wrote in message
t...
Since my original posting I have learned that the Commander HF-2500 uses
Eimac 3CX800A7 triodes, whereas the QRO HF-2500DX uses Svetlana
4CX800A/GU746 tetrodes. Some sources have stated that the IMD figures for
the Eimac triode in a grounded-grid configuration are better than the
Svetlana GU746 tetrode in grounded cathode grid-driven mode.



John,

IF I remember the old web sites both companies had a few years ago --
shortly after the split --
one took the TRIODE route (Commander) the other (QRO) the TETRODE route.

The rest is amateur radio history!

gb

Jhon ,

Did you take a look to Acom-amps ??

I had the Acom 1000 and now the Acom 2000 with a lot of joy.
I made some nice pics of both amps and you can see them on my webpage :
http://www.pa3hgt.nl



--
Met vriendelijke groeten,

Hans Pluijgers

callsign : PA3HGT
http://www.pa3hgt.nl



Seriously, thank you for your comments. I am not sure how
soon I will move on getting an amplifier like this, but
right now the HF-2000DX is at the top of my list. This
amplifier got very good reviews in eHam.net.
X-rated Vermonter wrote in message
...
On Mon, 18 Dec 2006 17:32:47 GMT, "John, N9JG"
wrote:

How do you prevent getting a hernia when you lift the
amplifier onto the shelf above the desk?

+++++++
It stays on the desk. If you want a lot of transformer,
the result is a lot of weight. I might add that, while
the tune up process is a little different, this
amplifier has highly repeatable tune settings, so you
just keep a little cheat sheet to tell you the tune and
load positions for each band.

Hans, thanks for the information. The Acom 2000 appears to be an advanced
amplifier and has received vg reviews on eham.net. It is difficult to find
pricing for this amplifier, but from what I can tell it is at least $1500
(USD) more than the QRO HF-2000DX. Of course the Acom 2000 has many
additional features (and complexities).

BTW, you have a very interesting website.

73 - John, N9JG

"PA3HGT" wrote in message
...
Jhon ,

Did you take a look to Acom-amps ??

I had the Acom 1000 and now the Acom 2000 with a lot of joy.
I made some nice pics of both amps and you can see them on my webpage :
http://www.pa3hgt.nl



--
Met vriendelijke groeten,

Hans Pluijgers

callsign : PA3HGT
http://www.pa3hgt.nl

[snip]

Hello John,

Thank you very much for the compliment.
The website is only in dutch 'cause my english is not so good but a photo
says more then 1000 words i think.
Acom 2000 amps are rare too find on the second hand marked.
For more info ... ask your friend Google , HI.




--
Met vriendelijke groeten,

Hans Pluijgers

callsign : PA3HGT
http://www.pa3hgt.nl



Hans, thanks for the information. The Acom 2000 appears
to be an advanced amplifier and has received vg reviews
on eham.net. It is difficult to find pricing for this
amplifier, but from what I can tell it is at least $1500
(USD) more than the QRO HF-2000DX. Of course the Acom
2000 has many additional features (and complexities).
BTW, you have a very interesting website.

73 - John, N9JG

"PA3HGT" wrote in message
...
Jhon ,

Did you take a look to Acom-amps ??

I had the Acom 1000 and now the Acom 2000 with a lot of
joy. I made some nice pics of both amps and you can see them
on my webpage : http://www.pa3hgt.nl



--
Met vriendelijke groeten,

Hans Pluijgers

callsign : PA3HGT
http://www.pa3hgt.nl

[snip]