Author Topic: Linear Amps another look  (Read 3616 times)

k4lrx

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Linear Amps another look
« on: May 18, 2015, 03:08:31 PM »
Linear amps Another look.


I had such good response on my first article on Linear amps I decided to write a second version of  my thoughts and the latest brands of linear amps. I also want to comment on tube prices for some of the most popular amps and the solid state amps on the market today.

I have checked Alpha, Acom, Ameritron to see what is new in the linear world, what I have felt is the big three are still clinging to tube technology and not making an effort to move into the solid state business at all in the last few years.


Let’s take a look at some of the amps just the type of tubes they use and replacement costs. 3-500Z I am looking at prices of these tubes on the internet and they are around $150.00 each, last price I saw was $158.00 each. By the time you read this the price may have gone up. Now let’s look at the real cost, one should replace both tubes in your amp, so double the amount of money for one tube. So, to replace both tubes in that vintage amp, namely SB 220 you will spent over $300.

811A tubes I found prices on the internet vary, but good Taylor tubes are going for about $32.00 each, so if you have a linear with four of these tubes namely an Ameritron AL 811 replacing all four tubes will cost you $128.00 now matched pairs a little more and one should have matched pairs of tubes.

3CX 1500 Rebuilt goes for $665 while a new tube from Eimac goes for $1450.00.

3CX 1200 Eimac really scares you, one tube $1229.00.

But the real kicker is 3CX800A7 this tube is used in some of the Alpha amps, namely the Alpha 86 and lots of hams have them. If you can find any one that carries this tube, good luck, it took me about twenty minutes of searching and only then did I find one seller of these tubes. The price was $321.00 each. The Alpha has two of these tubes, good luck on finding them, but you will spend about $650.00 to replace the tubes in this model.

Now who has what available as far as solid state amps?   Ameritron has their AL 1.3 kw unit for about the same price as their Al 1500 However, the reviews on this amp have been less then stellar or outstanding. It seems a 12 Volt power supply exists in the unit. It has been a source of problems and often fails with loud bangs coming from the main power supply. The reviews I have read about this unit are less then average, most of the complaining states this unit has spent more time in the Brown Truck going back and forth to Ameritron for repairs then it has in my shack! 

It cost some big bucks to ship this box back and forth, average operating time is short before another problem develops. Personally, I am staying clear of this unit. Yet some swear by it and others swear at it, the negative comments have turned me off of this one.

Icom does have a solid state 1KW amp in production, IC PW1 but try and find it. Icom does not promote the PW1 in their adds in QST, in fact I was not sure they had one since so little information is available. Their cost is around $5000, but it does only one KW. Comments have been from good to terrible, but why Icom does not promote it more is a mystery. Again, in the comments this unit has gone back and forth in the Brown truck a lot.

About two years ago I purchased a Tokyo High Power HL 2.5 this one has been trouble free and I have used it hard in contests, and every day operation. Not once has it given me any problems, it just keeps running. The bad thing is THP closed their doors for good about a year ago and left a big gap in the industry of solid state amps.

As a good note, the remains of THP has been taken over by Baofeng and we may see models surfacing close to the THP units.

I am looking for a replacement for my Alpha 86 I use it on my second rig for 40 meters, to be honest with the scarcity of 3CX800A7 tubes and the soaring price I am considering replacing it in the next few months.

So what do I have in my eye, I am giving serious thought to the SPE EXPERT 1.3 AMP.  this is quite a machine!  No tubes, solid state, fully automatic. Price is just a little more then the Ameritron AL 1500. Plus the Expert has six meters, a band I do work now and then when it opens.

This means I can sell off my 70 amp Astron  my TE six meter amp and two meter rig I seldom use, I really have no high power plans for two meters, or anything more then an occasional FM contact. Plus I plan to sell off the Alpha 86 at a good price, but not just yet, we will wait about two months.

So, there you have it my friends, The SPE Expert has had glowing reports and I am impressed with it, there is a unit with my name on it.

One more thing to mention, yes I have heard from some that tubes are more forgiving with less then average antenna systems. To me a big waste is load up an antenna with high SWR using a tuner. You are losing a lot of power in the inductive net work of the tuner I quite frankly have avoided antennas that are not properly tuned for the band I want. I have a 40 meter folded dipole at 70 feet, the SWR is 1.1 over most of the band and only rises to 1.3 at the very top of the phone band an area where I seldom operate. On 20/15/10 meters my Bencher Skyhawk at 80 feet is very resonant over all of 20/15 and passable on the very very high end of ten meters. Again, an area I do not work, or have any intentions of using the band above 29 Mhz.

Personally, if I purchase the Expert in the next couple of months I will get the unit with no antenna tuner, I simply do not need it. Stand by for a product review of the Expert shortly.
« Last Edit: May 20, 2015, 05:35:27 AM by k4lrx »