[AMPS] Purchase Recommendation?

[Marty Tippin]

Thanks for all the responses - here's a summary of what I received,  along
with another question or two I have:

* Heathkit SB-220 was the overwhelming recommendation, given my constraints
(see below). Price rumored to be between $400 and $600. Covers 80-10 only.

* Drake L4B and L7 were the second most recommended. 80-10 and 160-10,
respectively. 

* Here's what Carl KM1H had to say - pretty much covers it all:

>If you are into a gamble the MLA-2500 is a great amp, just make sure you
>get a guarantee with the tubes ! No tuned input and needs a simple choke
>mod for 12M.  $400-500 with decent tubes.
>
>Cheap money and relatively safe are the AL-80 and Heath SB-1000. Works
>all 9 bands at about 1KW on CW. $450-600.
>
>Drake L4B and L-7. $450-700 on the sold market. 80-10 and 160-10
>respectively. all WARCS also.
>
>KW TL-922 and Amp Supply LK500ZC. Both 160-10 and WARC. $700-900
>
>Stay far away from the MFJ/Ameritron 811 amps.
>
>Pretty hard to go wrong with any 3-500 amp.
>
>The MLA will cost you a second mortgage to retube but perfect ones can be
>had for $450 or so for that reason. 
>
>Same holds with many 8874 Alphas; big bucks to retube but a good one will
>last damn near forever if not overdriven. Good 2 holers are $700-800 and
>3 holers are about a grand. A bit more for the no tune versions but dont
>waste a premium on them.


Questions: 

What's all this about parasitic oscillation, etc, with the SB-220 and do I
really need to worry about it?? Any other things I need to ask the current
owner if I find one I'm interested in?

Do I need to worry about whether the ALC is compatible with my rig, or do I
just throttle back the output power so as to never overdrive the amp? The
FT-920 has a menu setting where I can limit max output power to anything
between 10 and 100 watts.

Rich pointed out that since my FT-920 has fast T/R switching, that I *do*
need to take the QSK capabilities of the amplifier into consideration. It's
my understanding that QSK really only applies to full break-in CW - I
generally operate phone and RTTY only so won't be doing a lot of rapid
switching betwen tx and rx. So do I really need to worry about QSK or not?


Of the recommendations, I think I'm leaning toward the Amp Supply LK500ZC
or Drake L7. Kind of shy of home-built stuff for now (spent months fighting
with my SB-200 on 10m and gave up on it...).

Thanks again to all!

-Marty KI0LO
 martyt@pobox.com



At 07:49 PM 4/28/99 -0500, Marty Tippin wrote:
>Looking for recommendations on an amp to buy, given the following:
>
>* Around $700. Wish I had a lot more to spend, but that's not likely to
>happen...
>* 1KW output or so - certainly no less than 800w, legal limit would be nice
>* Commercially made
>* Compatible with my FT-920 (i.e., low input VSWR, compatible ALC, and T/R
>relay switching without any fancy tricks)
>* 120 or 240VAC operation
>* QSK is not a consideration




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