[Amps] The cost of amplifiers, radios

[Paul Baldock]

My main amp is an ACOM2000A. But when I need instant on for  a QUICK 
qso I use my backup amp the L4-B. I run 3400V on the plates in the 
L4-B and comfortably get 1500W on SSB and CW. I have the original 
cooling fan, so I do not use it for RTTY.

I have no interest in cheating and running more than the legal limit. 
By the way for those that don't know, our legal limit on 30M is 200W PEP.

- Paul  KW7Y



At 09:04 PM 12/5/2016, Jim Thomson wrote:
>Date: Sun, 4 Dec 2016 16:27:18 -0500
>From: "Mark Bitterlich" <markbitterlich at embarqmail.com>
>To: "Bill Turner" <dezrat at outlook.com>, "Amps group"
><amps at contesting.com>
>Subject: Re: [Amps] The cost of amplifiers, radios
>
>
>Bill,
>
>The Henry 8K does 160, and all WARC bands.  Of course it is also pretty
>expensive and out of production.  Also very heavy, but you can remote the
>power supply and RF Deck from the operating position by quite a distance.
>And yes, it has a loud fan.  Just my own personal opinion, but I believe the
>tube it uses (3CX3000A7) is actually one of the best on the market .....
>cheap for the power it develops.
>
>You are correct, the majority of the other models do not do 160, and use
>individually switched Pi Input "modules" that make operation on some of the
>WARC bands less than a "plug and play" operation, not to mention the tapped
>coil(s).  Still, they are pretty amazing amplifiers.  Just saw a Henry 5K
>Classic for sale for $3000.  Two 3CX1200A7's (sadly, now a pricey tube), but
>it will also put out serious power.
>
>I really like the idea of cheaper amps with one pre-set for each band,
>(common parts, etc.) but logistically hooking them all up to one exciter
>would tend to be a PITA.
>
>Obviously I own an 8K and enjoy it very much.  I have tuned it into a 4.5:1
>VSWR on 160, with 1500 watts out on CW to work Navassa (an 80 meter OCF, was
>all I had at the time!).  Worked perfectly.  No computer controllers
>protecting it, so if you get REALLY stupid, you let the smoke out.
>
>Mark
>WA3JPY
>
>## The  3CX-3000A7 tube used in the 8K  and other amps is a superb tube.
>IMD3 is  -59db pep...at 5 kw pep out..and more and lower power levels.
>Instant on, rebuildable tube.  50 ohm input.  225 w CCS
>grid dissipation, and even more when in GG mode, with grid bonded to chassis.
>You can use the grid as a dummy load for a FT-1000 D.   With 5 kw 
>out, the grid
>only dissipates aprx 80-90 watts.  Nobody ever blew the grid out of 
>a 3x3 tube,
>even 11m ops.
>
>The henry 3K ultra is also a 160-10m amplifier.
>
>##  typ 3CX-3000A7 in GG  with 4800-5000 under load runs as follows.
>50w in = 1.5 kw out.
>100w  = 2.5 kw
>150w = 3.5 kw
>200w = 5.2 kw
>
>##  the 3CX-3000A7 is still used in a lot of FM broadcast TX, like 
>energy onxix..and others.
>
>##  using several small amps, each tuned on a different band is 
>simple in most cases.  I string
>all 4 of my L4B amps in series, nose to tail.  Then either tune each 
>amp on a different band, or
>cw + ssb on  the same band, or cw and 2 x ssb segments, like for 
>80m, or any possible combo
>you can imagine.   Low bands at night, high bands during the daytime etc.
>
>##  That works, provided the amp in question will handle full power 
>on BYPASS  mode.
>
>##  I use a simple rotary switch, to switch the key lines to each 
>amp. IE:  keyline from xcvr to
>input of rotary switch.   Then 1 output to each amps key line, so 4 
>in all on the output of the
>small rotary switch.  Then only one amp can ever be keyed at any 
>time.   Dead simple,
>and effective.   If one amp ever blew up, I still have 3 
>spares.   Modifying a drake L4B to
>include  160m  ( in addition to 80-10m)  is not an issue either, 
>fairly  Simple really.   The oem
>156 uh plate choke is ample for 160m, as is the oem Bifilar fil choke.
>
>Jim   VE7RF
>
>
>_______________________________________________
>Amps mailing list
>Amps at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps