Amplifier advice needed

Gene A. Williamson genewill at
Fri Sep 27 10:02:29 EDT 1996

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> I'm shopping for an amplifier for contest use 2-3 times a year
> (i.e. away from home station). 600-800 watts and switchable 110/220


	I'm attaching a file that appeared on the reflector some time ago, with
suggestions for just such amplifiers. My vote is AGAINST the sweep-tube
amps, as those tubes are (1) delicate, (2) hard to find, and (3)
expensive. I've heard nothing but positive things about the Ameritron
AL-811 (3x811A) . . . one guy even wrote, "If I blow a tube, I just pull
it out and continue with the ones that are left." Give Joe, K8JP
(palooka at an email if he doesn't respond to your
question. He drags his AL-811 all over. I own an AL-811H, like it a lot,
and am planning on taking it with me on trips. Your next best bet, IMHO,
is an SB-200.

73 Gene K7dBV			genewill at

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Conference:	6	Email
Date: 		09-13-94	Time: 	19:03
From:		KA9FOX at           
To:		CQ-CONTEST at       
Subject:	SUMMARY- Best amp for DXp

>From owner-cq-contest at Tue Sep 13 17:04:49 1994
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Date: Tue, 13 Sep 94 19:03:07 EDT
Subject: SUMMARY- Best amp for DXpedition
Status: O

Thanks to the following for their much appreciated input:  AA4GA,
WB0GAZ, WB2K, WB4FLB, WB9TIY, WJ2O, and whoever Glenn mgvinson at is
(sri OM - no call listed on message).

If I can find one reasonably priced, it looks like the Dentron MLA-2500 amp
is the one to get.  Only bad thing about this amp is the price of replacing
the 8875 tubes.  Hope you find the following comments helpful:

DENTRON MLA-2500--------------------------------
     "I've owned lots of different amps, but I'd have to recommend
a Dentron MLA-2500 if you can find a good one. Why? It fits the bill of a
contester. First off it's 160-10m (no amp on 160 = wimp city). Second it's
full power, not just 600-700w. Third, hefty compact chassis. Not real heavy
considering what it puts out. Fourth, runs of 110 or 220v. Can come in
handy sometimes. Drawbacks...It runs 8875's which are hard to find, but I
ran mine for years without a problem. No tuned input, but I ran it with
rigs that didn't have a auto-tuner and it was fine." -WB2K
     "I bought an MLA 2500 for $425 for my XE trip. With the tubes that came
with it (well worn) it ran 700-800 watts 10-160. New tubes cost more than the
amp, so
that isn't worth it. It isn't pretty, but it is built like a tank and you
can't beat the price. I've seen them advertised on a regular basis in HTYS."
     "Here's a suggestion--and it's a suggestion only, because I won't part
with mine.  I have a used Dentron MLA-2500B I bought for only $400, and it is
exactly the item for expedition trips.  This thing will handle 160-10 and put
out just about a KW with 100w of drive.  It can be wired for either 110 or
220 very easily.  Most important, it is just small enough to fit under the
seat in front of you on a plane and so qualifies as "carry-on" baggage.  (But
it does take practice to carry  this thing around without showing how much it
weighs!)  This is the same kind of amp Lloyd & Iris used to lug around.  If
you can one for about $500, I'd say it was a fair deal.  P.S. I'll be
dragging this amp down to ZF8 for CQWW-CW" -AA6KX/ZF8BS
     "See if you can find yourself a MLA2500 that still has good tubes.  I
used one of those for 4 straight years in the Carib and racked up close to
100,000 Q's between contests and pre-contest operating.  Never had a problem.
 Damn thing was close to bulletproof.  CAUTION: You don't even WANT to know
how much tubes cost!!" -WB9TIY
     "Most guys I know bring a Dentron. They are smaller, lighter, and less
fragile. But I dont have one." -NU6S
     "Some old Dentron MLA2500 around that are 10-160m but they use EXPENSIVE
ceramic tubes." -KR0Y
     "I've been on several contest trips where we carried MLA2500's.  The
are expensive, and the power supply caps are sometimes a problem, and 
sometimes they arc....but  they're probably the best watts/dollar/pound
solution." -AA4GA

DENTRON GLA-1000--------------------------------
     "Watch out for the Dentron GLA-1000 series, which is very compact and
inexpensive, but costs lots of $$ to retube." -WB0GAZ
     "You know people will laugh but I have used an old Dentron GLA1000B when
I DXpedited years ago(ZB2 and EA8)-yeah I know it only runs 500W tops but its
easy to fix and the tubes are cheap and easy to find-runs on 120/220 etc.
 Heck they only cost $200-300 down your way." -VE6SH

DENTROL CLIPPERTON-L--------------------------------
     "This maybe out of your price range, but a Clipperton "L" may be the
ticket. These things are tough as nails if you get a good one and it is
painfully simple to deal with. I'm sorry I sold mine (VR2IH has it now)."
     "Clipperton-L  a good choice (10-160). I had one but sold it. Abt $350."

HEATHKIT SB-220/200--------------------------------
     "Believe it or not, the SB220 will fit under the seat infront of you. I
usually disconnect the AC cord for travel and attatch a handle.  So far it
has survived KH6, VP2M, P40,  with side trips to V2, KP4, KP2, PJ2 and
numerous trips to other W6 QTH's. It also has never let me down (unlike 2
different Alphas that I used during contests). Just be careful not to break
the 3-500's."-NU6S
     "If you wanted something bigger, but cheap and less power, I guess
and SB220, but that's a hog to haul around." -AA4GA
     "SB-200.  It is light, 110/220v, tolerant of bad antenna matches, and
fits  your budget.  We have used it in 2 rtty contests.  We have also used
bigger and more expensive amps which are very useful but don't fit your
criteria." -mgvinson at

     "In the early eighties I used an fl2100b for short dx trips.  They sell
used now for about $400. Uses a pair of 572B's."-W0CP
     "I suggest an old FL2100 series amp. Relatively cheap, can be hand
carried with appropriate mods for handle."-VE4GV

AMP SUPPLY LA-1000 / LK-500----------------------
     "Stay away from sweep tube amps. The're small but the LA-1000 I borrowed
and carried to 6Y5 land lasted all of 5 qsos."-VE4GV
     "I have an AMP SUPPY LA-1000 that I've taken on several trips. It uses 4
sweep tubes and puts out about 500 watts.  It is small in size and easy to
pack and carry on the trip."-WB4FLB
     "...or an AMP SUPPLY LK-500 type, 10-160 pair of 3-500Z.  Thats what I
have now, about 600 bux."-KR0Y

OTHER AMPLIFIERS--------------------------------
     "We took a 30L1 in its custom travel case with us to ZF8. It provided
of poop and travelled well, and I think it fits your budget."-K1KP
     "We ended up using Ameritron AL-811A's from VP2VFP. We had the 4 tube
version but with line regulation in the Carribbean you will be lucky to get
the full rate 600w output. I believe it weighs about 35 lbs, there is nothing
else in that weight class next step up is in 50lb - 75 lb range." -KU4J
     "Scott this doesn't really fit your profile but thought I would pass it
along anyway. I travel with my Alpha 76PA. I got the small hypersil for the
76A (1.5KVA). I have a old woodside suitcase that the Alpha fits in
perfectly. I take out the xformer and carry it on in a shoulder bag (gets
interesting looks at the X-ray machine). The 76PA in the suitcase survived a
eight foot fall onto concrete at the Guyana airport. You MUST get a VERY
reliable amp for traveling that can easily be converted to 120 or 220 volts."
     "I take my Yaesu FL7000 on most of my trips, but I hate it and it cost a
lot more than $400 to $500.  It is constantly tripping out it's protection
circuit (antenna currents have to be darn perfect), and I've never got it up
to the 600 watts it's rated for.  Typically run 300 watts out.  Even 300
watts is a hugh improvement over running barefoot.  The good things about
this amp are utomatic band switching and I can configure the wiring to
accept many different ac voltage inputs from 110 to 240." -WJ2O

MISCELLANEOUS COMMENTS--------------------------------
     "Some tubes are cheaper and more readily available than others.  Avoid
8874's. Some tubes are probably more rugged during transport than others.
 Avoid 4-1000's, 3-1000's, and maybe 3-500's.  Sweep tubes are getting
expensive. Watch out for the Dentron GLA-1000 series, which is very compact
and inexpensive, but costs lots of $$ to retube." -WB0GAZ
     "Power transformers are _heavy_, and when the amp is in shipment,
bouncing it around could bend the chassis or transformer mounting hardware.
Reinforce the appropriate spots on the chassis, and/or use an external HV
     "Don't believe the hype, run <500w in contests."-W0CP
     "If you are going to running off of generator power....avoid anything on
the new side for they don't like unstable voltages. I keep an Alpha 374 (not
the 374A) in top shape because its old, and it really pumps when being fed by
portable power. Not even a flinch. -- As a rule of thumb....avoid anything
with IC's for portable operation."-VR2GO
     "Bring a good tuner also. I picked up a used Drake MN 2700 that covers
10-160 for about $250."-AB6FO



>From tomf at (Tom Francis)  Fri Sep 27 18:03:17 1996
From: tomf at (Tom Francis) (Tom Francis)
Date: Fri, 27 Sep 1996 13:03:17 -0400
Subject: SO/SOA/MACHO comment
Message-ID: <199609271703.NAA02045 at>

Hi all:

A short comment on the SO/SOA/MACHO thread...

It seems to me that SOA ops SHOULD have an
advantage over SO ops by nature of the category.

This does not appear to be the case as eviden-
ced by the score boxes and comments here on the
contest reflector.

Therefore, it would seem to me that the true
methodology of operating SOA has not been found
yet by those operators who choose this category.
I am not saying that SOA ops are inept, just that
the optimums have not been reached.

Thanks for your time.


Tom, NM1Q (tomf at 

>From zs6brh at (Keith Radue)  Sat Sep 28 03:34:52 1996
From: zs6brh at (Keith Radue) (Keith Radue)
Date: Fri, 27 Sep 1996 19:34:52 -0700
Subject: CQ RTTY contest - ZS9C
Message-ID: <324C8ECC.4BF2 at>

Please note that I will be using the call ZS9C (My new contest callsign)
for the CQ WW RTTY contest.

Good luck to all.

  73, Keith (zs6brh at

>From tree at (Larry Tyree)  Fri Sep 27 18:39:23 1996
From: tree at (Larry Tyree) (Larry Tyree)
Date: Fri, 27 Sep 1996 10:39:23 -0700 (PDT)
Subject: The real question
Message-ID: <199609271739.KAA04256 at>

> It seems to me that SOA ops SHOULD have an
> advantage over SO ops by nature of the category.
> This does not appear to be the case as eviden-
> ced by the score boxes and comments here on the
> contest reflector.

Actually, the more relevant question is:

Do single operator unassisted operators who use packet (illegally)
have and advantage over single operator unassisted operators 
who don't use packet.

There is a difference in how a single operator assisted
person might use packet compared to a single operator
assisted person (ie: avoiding some of the less productive
uses - but still getting some benefit because he has access
to more information than the guy without packet).

I know I would be more productive as a single op if I had
that type of information.  

> Therefore, it would seem to me that the true
> methodology of operating SOA has not been found
> yet by those operators who choose this category.

Right.  This is just another way of saying the better 
operators tend to gravitate towards the non assisted

> I am not saying that SOA ops are inept, just that
> the optimums have not been reached.

I suggest they are being reached, but maybe by people who are 
checking the wrong box on their summary sheet.  I think if 
you read between the lines on Dick's posting you realize that
some people are obviously cheating.  The data is there.  The
question is do we want to do something about it?

I find the arguement that this is a fun thing and we shouldn't
wasting our time checking logs to be...   well, how would you
feel if you have invested hundreds of hours of your time advancing
the tools so we can check logs better and people just tell you 
it is a waste of time.  How would you feel if you have refined
your operating ability so you don't make mistakes and people
just think shouldn't matter.

True, we can do much about some things (power and so on), but we
have tools that give us a pretty good idea what is going on with 
many other aspects of the log, and I think we should be able
to use them!!

Tree N6TR
tree at

>From at TGV.COM (morpheus at  Sat Sep 28 00:56:05 1996
From: at TGV.COM (morpheus at (morpheus at
Date: Fri, 27 Sep 96 20:56:05 -0300
Message-ID: <199609272356.UAA22776 at>

Hi everybody,

  I will be joining CQ RTTY Contest this weekend starting 17:00 UTC, I hope I
can give every one points in this contest!! the Qsl card will be OK via the
Bureau or direct to: Hamad J. Al-Nusif P.o:29174, 13152 Safat Kuwait

thank you

de 9k2hn

9K2HN            | E-Mail: morpheus at                          |
Hamad Al-Nusif   |   |
P.O.Box:29174    | Phone: (965) 2562561 between 0900 to 2000 UTC    |
13152, Safat     | Mobile:(965) 9060495 if I'm not home!!           |
Kuwait           | Fax:   (965) 2570014       24 hour a day!!       |
                 | Packet: 9K2HN @ 9K2HN.KWT.AS                     |

>From rlboyd at (Rich L. Boyd)  Fri Sep 27 19:15:32 1996
From: rlboyd at (Rich L. Boyd) (Rich L. Boyd)
Date: Fri, 27 Sep 1996 14:15:32 -0400 (EDT)
Subject: SOA not as tough as SO
Message-ID: <Pine.SUN.3.91-FP.960927140709.10381C-100000 at>

The theory I have stated to a number of people on why SOA scores have not 
been as high as SO scores is that the majority of big gun ops with big 
gun stations go in the SO category.  Some of the perenniel top SOA 
stations are more modestly equipped than the perenniel top SO stations.  
K3WW, as I recall, has a couple towers that are pretty close together, 
not super tall, with tribanders and maybe a 2-el 40.  The top SOA in PVRC 
lately has been N3RR, who has one big tower that he's been equipping with 
monobanders, plus his old small tower with a smallish tribander.  Maybe 
this fall he'll really hit his stride with the new tower.

Anyway, both these stations that I know of tend to be somewhat smaller 
than some of the top SO stations.

I agree that band hopping for the whole contest for every mult that comes 
on the air may sometimes decrease your score (even significantly).  Some 
SOA stations, like N3RR, mult hop quite successfully but have trouble 
running.  SOA or SO, you gotta run if you wanna score high.

But, I think if you were able to take the top 10 SO stations and have 
them all go SOA in a particular contest, they would all score higher than 
they would otherwise.  And...I personally feel the skills they'd have to 
use would be as great as the skills they used SO.  But...the skills would 
be somewhat different than the SO skills.  They'd have packet advising 
them of possible band openings and mults on the air; they'd have a 
different judgment decision equation, though, with those additional 
inputs, as to whether, in fact, to change bands or whether leave a run or 
distract themselves from a run by working the mults.

I think SOA is no less macho than SO, but it's somewhat different than 
SO.  If the top 10 SO guys would go SOA, the SOA category would be the 
prestigious category, in my opinion.

73 - Rich Boyd, KE3Q

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