The AM Forum

Got the 220v installed in the new shack and am thinking of upgrading to a good strapping QRO box to use with the Flex 5000.

160 a must
6 would be nice
Well built, solid reputation.
Prefer tubes but open to sandstate

Interested in thoughts.
Thanks
Carl
WA1KPD

160 to 6 and hollow state will really limit your choices.

The amps coming out of commie eastern block (Acom) seem to fit the bill.

Solid state the choices really open up, with the range of frequencies your looking at.


--Shane
KD6VXI

I've been using a Drake L-7 for years: 160 - 10 Meters using a pair of 3-500Zs. It's a solid performer that can be had for reasonable money. The only limitation is that they won't run today's legal limit due to PS voltage limitations, but that's not a problem in my eyes. I can probably push more power out of it, but I'm comfortable feeding it with around 12-15W for 250W carrier output on 80M. The additional 1.7 dB needed to get you up to legal limit can cost you a lot of money.

Build it! Three 3-500Zs seems to be better than the usual two, a moderate yet AM-durable full power approach. Someone here did a triple like that IIRC and was pleased.

Pat, would love to but have a bunch of ham and non ham projects ahead of it so I am willing to pay the extra $$ for a new or good used one. So far the L7 seems to e the only one used..... :)

Could you state more details on size, weight, price, power?

Hi Steve,
Price size weight etc area all open for consideration including new or used. Do not want something BC size. I just don't have time to build, modify, or take on a project.
The only must haves are:
-160 meters,
-Well built with a solid reputation
-Must cover 160. Only real use will be to comfortably bring output of Flex 5000 up to legal AM without stressing components.
I have an AL80B now and it is huffing and puffing so I want to move up now that I have 220.

I know lots of guys are using them so I am interested in experiences, recommendations, warnings etc.
Thanks
Carl

Hi Carl,

You posted as I was writing this and  I see you don't want to build an amp. But here's my comments anyway...


The Flex 5000 now has its own version of "Pure Signal" right?  This opens up the whole world of using cheap, dirty, solid state amps that can be cleaned up in software.

Sell the AL-80B and convert it into sand...  I would start with a common 600 watt PEP 6M-160M transistor  amp. (use as a driver later)  Use this in the interim while you take your time to build up a monster solid state amp using the latest RF solid state power modules on the market. Shoot for 5KW output and run it cut way back to the 2.5KW PEP area.   This will make it clean and bulletproof on AM.

Maybe the Flex can drive some of these newer modules directly without the 600 watt IPA, I dunno.

Using the latest softwares, you will have the convenience of instant band switching and the cleanest signal on the band... -55dB 3rd IMD, etc.

This is a high power amplifier lash-up that could last the rest of your life and require little maintenance.... reasonably lightweight too.  

T

Hi Tom,
No time to build in the foreseeable future so I am open to buying. The advantage of SS is most of them seem to go up to 6. But wanted to get feedback from users before I shell out those sort of $$.
Tnx for the feedback
Carl

I've been pretty happy with an Ameritron 1306 so far. I drive it with a Anan200D to about 200 watts carrier or a bit more. 160-6 meters. It replaced the TenTec Titan 425 that got nuked in the lighting strike. So far I like it better. Easy to run, quieter, not quite as much outpoot, but I can't really tell the difference. I use it a lot more than I ever used the Titan because it's just handier to flip on and go. All I have to do is make sure the drive is turned down if I've been running barefoot.

Hi Carl,

I have an Ameritron AL-82 that I really like.  I bought it about 20 years old and has the same set of tubes in it.  It easily does the 375W carrier power.  Al-W1VTP has one and really likes it as well.  

I donated to W1AW my new Alpha 8410 that ran a pair of 3CX1500's.  I kept it about 6 months and then decided W1AW needed it more that me for their 160M bulletin station.  It was a very nice amp but I really like my AL-82 better.

Joe-GMS        

Get the AL82 if you want tubes.  It's about all that is left, new.

An AL 1500 if you really want legal limit am. Add a muffin fan.  The AL 1200 is a better tube, if you have the additional drive.

Otherwise, your looking at either flex legal limit or the new kpa1500.

Or, spend your money in euros. That won't make Trump happy though.

Dishtronix Prometheus is a great amp.  If you can afford it, I'd go Harris or some other real mil spec company.

There is a KICK ASS Homebrew gs35b for sale on the ham sites today.  A competent builder did it, it's his personal amp.  He's moving into an rv and can't take it with him.

--Shane
KD6VXI

OM Power has some interesting products if want tubes.

SPE Expert Linears have some nice solid state amps. I've heard tons of these on the air.

I'm using an ACOM 1000 with my Flex 6500. 250W of carrier - absolutely no problems for past two years. Super easy to tune and the tube is very inexpensive. I think it's one of the best bangs for the $$

I know you want to buy rather than build, but I built a triple 3-500 linear. It was super heavy duty and much cheaper than the commercial two tube offerings. It was awesome and I wish that I hadn’t torn it apart.

Jon

Carl,

Here's another vote for the AL-82, which does a fine job of forcing lots of air up through the tube sockets and chimneys to keep the pair of 3-500's nice and cool during AM linear duty. The power supply is the heart of any linear and the AL-82/1200/1500 get high marks for ruggedness. I grabbed a used fuse blower locally 8 years ago for 1200 bucks and after replacing the bleeder string and the blown PS caps it has run great. An AL-1200 or AL-1500 would also be fine but they tend to be more expensive.

I would also agree that the ALS-1306 (using 8 x MRF-150 FET's) is a nice solution for AM linear from 160 through 6 meters. It handles 200 - 250 watts of carrier with plenty of headroom for positive peaks. The implementation of temperature compensation in the FET bias circuit of the ALS-1306 really works well when running high duty cycle modes like RTTY or AM linear. I grabbed mine at HRO last December when they were running a sale and as Kevin mentioned above, the ease of use is very addictive!

73,

Rob W1AEX

It may do a good service to point out linear amp models covering 160M that, while they usually work properly or are beautiful to behold, have known problems or "inadequacies", or caveats on AM. Be most helpful a new buyer before the fact.

Nothing intended to be unfair to manufacturers, if there are factual problems or multiple failures behind the comments they should speak for themselves.

non-offensive comments like these, (disregarding 160M)

1.) The SB-220 is a bit light on the power transformer, and the cooling of the tube bases and filament pins is marginal and has caused desoldering of the pins from the tube leads.

2.) The NCL-2000 uses two $400 tetrodes with delicate screens, and it has a metering issue that may let excessive screen current and other measurements go unseen.

3.) SDP-1000L is large rackmount size but makes only 500W PEP on SSB, covers 2.2-28MHz, and does not include an RF T/R relay.

All good amps listed here in this topic, but the buyer ought know about any caveats others may have experienced, before he chooses.

https://forums.qrz.com/index.php?threads/b-w-barker-williamson-pt-2500a-amplifier.614649/

Something like this might work for you.

I'm moving to the area mid month, I could help with picking it up, shipping, etc. If needed.  Seems like you sent me a knob or something years ago I needed.....

--Shane
KD6VXI