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Six used Affordable HF Amplifiers worth Considering

Discussion in 'Amateur Radio Amplifiers' started by N8FVJ, May 19, 2019.

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  1. G3YRO

    G3YRO Ham Member QRZ Page

    Well I spoke to dozens of TL922 owners before buying mine a couple of years ago . . . and nobody had anything but praise for them!

    The bandswitch in the TL922 is much the same as in any high power amp.

    At the end of the day, ANY amp can have its bandswitch destroyed if it's been abused !

    Roger G3YRO
     
  2. N8FVJ

    N8FVJ Ham Member QRZ Page

    Here are issues as shown on eham reviews. The band switch is unobtainium in NOS.

    #1:
    'This amplifier seems to have a cult following. Theres no doubt that its physically well built, however electrically its an marginal amplifier.

    The prices that people are asking for these amplifiers borders on insanity for such a old weak amplifier design.

    The many faults include

    Poor RF design
    Poorly rated RF parts
    Poor or NO protection circuits
    Lots of trouble with parasitic problems
    No spare parts available
    Tubes that are getting expensive

    If you ran this amp in a contest you will probably burn it out.

    If the bandswitch or power switch goes you in deep trouble. If you have a grid filament short you could be in for some real trouble. None of the spare parts are available.

    The load C spacing is marginal, if you even try and tune it into a moderate 2:1VSWR you will ARC this crappy capacitor.

    The relay switching is slow and will damage newer model radios. No inrush limiting and many other design failings.

    Just do a google on the TL922 and you will come across several pages on "mods" to try and correct its many design failings.

    I like buying blown up TL922's and converting them to 6 meters. However on HF I would only recommend the TL922 to my worst enemy. If you have one keep it, however I would not invest money in such a marginal amplifier.

    Today if I was looking for a 1 kilowatt to 1300 watt amplifier I would be looking at one of the new solid state designs like the SPE or Ameritron.
    If you need a real 1500 watt amplifier get the AL1500.

    Bottom line is that I hate using equipment that makes me nervous every time I turn it on or use it. The TL922 is such a beast, its better to look at than USE!'

    #2:
    'In my opinion, this is one poorly designed amp. The amp has poor cooling from poor air flow. Result is every thing gets hot inside. But the biggest problem is that this amp is unstable. Alot of users have complained about parasitics but I found this amp wants to oscillate. After spending a week adding some suppression, I finally ended up neutralizing it using the method that 572 amp makers have used. Now, the grid and plate current meters don't move when they should not show any change. I sold this amp after modifying it.

    Buy this amp if you like spending alot of time working in a HV compartment for a week or two, if it doesn't take off and do a melt down before you get started. If anyone gets a tendency to want this amp, go buy a L4B or an L7.'

    I do not find reports like this on the TL-922 with my recommended HF amplifiers. A Drake L4B or L7 is a far superior HF amplifier after being rebuilt. So, buy a rebuilt Drake for $800 or my recommended two 3-500Z tube HF amplifiers if you want 1200+ watts PEP output. Unlike ICOM and Yaesu, Kenwood dropped out of the HF amplifier business after this TL-922 HF amplifier.

    Final statement Kenwood TL-922:
    Not Recommended.
     
    Last edited: May 29, 2019
  3. G3YRO

    G3YRO Ham Member QRZ Page

    Well I disagree totally with those comments . . . and neither have any of the TL922 owners I spoke to had any problems (and neither have I since owning mine).

    You can find negative comments about ANY piece of equipment on the Internet, as some people are very biased or inexperienced. But there are also lots of positive comments about the TL922 too.

    I certainly prefer it to the Drake or Heathkit amps . . . and the Ameritron Amps are very cheaply built by comparison.

    Roger G3YRO
     
    Last edited: May 29, 2019
  4. N8FVJ

    N8FVJ Ham Member QRZ Page

    The Ameritron AL80A and AL-80B are not cheaply built by any means. No band switch arcing on my recommended HF amplifiers per all reviews at eHam. Some HF amps like the Yaesu FL-2200 have band switch arcing too.
     
    Last edited: May 29, 2019
  5. N8FVJ

    N8FVJ Ham Member QRZ Page

    Reason for Kenwood TL-922 band switch arcing per eham discussion.

    'Over current is not the reason those switches fail. It is because the wafer that attaches the added capacitors to the high side of the final tank are not rated for the peak voltage attainable'. KM1H replaced eleven TL-922 band switches.

    If you have a Kenwood TL-922 band switcvh failure, use this.

    Skip at Multi-Tech Industries has a New, Superior Band switch for the Kenwood TL-922. His New Band Switch is Much stronger and Bigger the the little Original Kenwood Switch, yet it is a Drop in Replacement. The Switch is Available for immediate shipping. I have one in my TL-922 and I am confident, I'll never have Band Switch problems again with this Amp. This is a Fantastic improvement for our TL-922 Amps. Everyone knows that the Original Band Switch is the Weak point in the TL-922 Amps.
    http://multi-tech-industries.com/
    Email Skip at Multitech@sprynet.com

    73,
    Gordon
    N6WK
     
  6. G3YRO

    G3YRO Ham Member QRZ Page

    In my experience, bandswitch arcing is normally down to misuse . . .

    I had a Yaesu FL2100 for 40 years and never had ANY arcing . . . and never had any on myTL-922 either.

    But I have seen arcing in Ameritron amps I've repaired.

    Roger G3YRO
     
  7. N8FVJ

    N8FVJ Ham Member QRZ Page

    No reports of Ameritron 3-500Z amps band switch arcing on the internet or on eham reviews. So, only you seem to have Ameritron AL-80A & AL-80B band switch arcing issues. Stay with your TL-922. I would not buy one for $300.
    The Kenwood had 11 band switch repairs from one ham and noted others replacing the entire switch. Many mods for Kenwood TL-922s vs very few mods on AL-80A & AL-80B.

    For the rest of you, stay with my HF amplifier recommendations. You will not have issues, just many years of reliable operation. I also have to consider many of newer and some older hams do not have the skills to rebuild or modify HF amplifiers like Roger above.

    Yaesu FL-2100 issues per eham.

    #1
    I was surprised to see these rated above a 4.
    Probably because the only survivors are the better examples of an overall poor design. Many parts seem overly vulnerable to failure including the fixed capacitors, meters, HV rf choke, parasitic suppressors, band switches, tubes, etc. Good grief, I even had to drill out half the screws just to swap out bad parts. I also see several mods, including full blown websites devoted solely to reworking these bombs.
    Mercifully, my shack is now 2100b free and I will happily survive with my trusty sb-220 and al-84 amps.

    #2
    It can work well and looks good but,...bandswitch is wimpy, burns out. The amp gets REAL hot, you need to bolt on a extra fan, it helps a lot.
    The Ameritron 811 goes for about the same money and is a little less problematic.
    Bottom line on these things, they are a cheap way into amp land.

    #3
    I do not like it because it burns the bandswitch easily. I owned two FL2100B´s and one FL2100Z from 1992 to 1996. The three of them had the bandswitch damaged! It also gets so hot that you can fry an egg on it after some minutes of transmission. Today I own an Ameritron AL80B and an old SB220 and I like them both very much
     
    Last edited: May 29, 2019
  8. G3YRO

    G3YRO Ham Member QRZ Page

    I don't mean any disrespect, but it seems to me that you have a lot more Amateurs in the US who don't know how to use Valve Linear Amps properly, if they keep burning out their band switches !

    As I say, I've used Amps for over 40 years and never had one burn out.

    Roger G3YRO
     
  9. N6UH

    N6UH Ham Member QRZ Page

    I suspect that different allowable power levels in the UK and USA have much to do with the failure levels too!
     
    N5WVR and KD2ACO like this.
  10. N8FVJ

    N8FVJ Ham Member QRZ Page

    That is correct as Roger is limited to 400 watts out in England.
     

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