Anyone have issues with Amplifiers?

Discussion in 'Amateur Radio Amplifiers' started by K3SK, Mar 19, 2020.

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  1. K4AGO

    K4AGO Ham Member QRZ Page

    They say that after the first two shots, it's all good. Personally, I wouldn't know. :cool:
  2. VK4TI

    VK4TI Ham Member QRZ Page

  3. K0GWA

    K0GWA XML Subscriber QRZ Page

    Might be worth while to join the EB2499 SSOA group on Facebook, a lot of unhappy owners, I being one of them. On my second set of FETs in 6 months.
  4. N0MJP

    N0MJP Ham Member QRZ Page

    I bought a pa1200 version... I started with the just the populated board... I bought a Flatpac2 power supply to run it.. it was present to 53.5 volts at 50 amps I believe... I bought a heatsink and copper spreader and went to drilling and tapping holes.. I set the the bias to 1amp and did a test at 12v and low wattage input to make sure the blf188xr was turning on properly... I then decided I wanted the protection , tantum match filter board and meter.....I installed a 10db attenuator as recommended (note: there is already 3.86 db already on the populated board) and I fired it up without the protection boards to see what it would do... slowly increasing the power until I got about 800 watts ssb then I put the filter board in line and raised the power until I got 1000 watts..with about 24-26 amp draw...

    I then hooked up the protection and tantum boards and the over current and swr lights came on and shut down the amp... I figure I have a bad coax in the amp somewhere and haven't gotten around to look for it yet...

    Couple notes.. if you are building this amp without protection...then make sure you put 20 db in front of the pa board you won't blow up the transistor... the output side is nearly indestructible.... however the input (gate) side you do not want to push it over about a watt.. So with a 20 db attenuator your 100w rig won't blow up the transistor... that means with the 3.86 on the board plus a 16db you should be close enough to 20 db..

    This will keep you from doing what most new builders have been doing and blowing up their Blf188xr go over 2 watts of input and you'll smoke that chip.... also.. I mocked up the attenuator that was on the board with 2 10ohm resistors and a 100ohm .. and put it after the 10db attenuator and then hooked it to my rig and a dummy load and logged all the wattages at various settings..

    Victor and Yamon know what they are doing and have and excellent board .. w6pql also has a nice board altthough more expensive... 73 es gud luck N0MJP
    KD2ACO likes this.
  5. K3SK

    K3SK Platinum Subscriber Platinum Subscriber QRZ Page

    I've been running the EB104 1200 watt HF-6 amp vey hard for almost a year now. Its operated nearly flawlessly. I run it for SSB with about 80 watts or so drive and get 1200 watts output. For digital I've run up to 30-50 watts with no problems at all. I do watch the internal temperature when running digital and usually take a few minute break if it displays above 42º C. The internal cooling ban and the "heat pipes" work very well and it drops to below 30º very quickly.

    It turned out that the noise I mentioned on transmit in a post above was being caused by the pulse width modulator from my 13.8 volt power supply. I was using my Kenwood PS52. Replacing it with a different power supply eliminated the problem. I also wired a reset for the protection board to the unused contacts on the front panel switch. Doing this allows me to reset a fault just by flipping the power switch off, then back on without disconnecting or powering off the 50 volt supply. Its about the same as having a "standby' switch.

    Still don't have my VHF towers up with the SSB 2-meter yagis but I did try it on the 5 element I have and with 30 watts drive (amp is rated for 50 watts max) I get the full 1 kw output.

    I also snagged the EB104 432 500 watt amp on eBay. A guy in Florida bought 2 of them and was going to use combiners for more output and apparently it didn't pan out and I got the perfect, like new amp for far less that it would have cost me to buy it from Victor. It is set up for a max of 8 watts drive, so I am adding an additional internal attenuator to protect it in case I screw up and run the full 30 watts from my rig into it.

    I do like thses amps and the sure take up a lot less space than the old 4CX250 amps I had been running on VHF/UHF.

    de K3SK
  6. N0NSX

    N0NSX Ham Member QRZ Page

    Boy, it's almost a year since our last posts. How is your Amp working? a buddy of mine bought the complete EB1200 amp. He couldn't get it to fire up, so he sent it for me to have a look see. The amp is well built, a lot of stuff in a small box. His manual doesn't show that it needs the external 13.8 ps, and is block diagram shows a dc-dc buck converter and his pinout on the db25 doesn't show that the 13.8 connects to it. So I traced down the wiring and found that a separate supply is required, should have read your post, HIHI. He bought a Meanwell 50 amp supply that has a remote turn on. I found a DC buck converter on Ebay for 7 bucks, must have went up in price. My question Do you have any issues with the adding the DC converter, wonder how much EMI these little switches put out, and turning the 50 volt supply and converter on and off at the same time with front panel switch?. I am not sure why Victor doesn't have a converter already installed, since there so cheap, when you pay $1400.00 for an amp .
  7. K3SK

    K3SK Platinum Subscriber Platinum Subscriber QRZ Page

    First, my amp has preformed flawless since first using it. Even thought the amp is spec'd at 53 volts DC I have a 55 amp server supply that I run at 50 volts. I run it hard on all bands using SSB at 85 to 90 watts input and at 30 to 40 watts drive when chasing DX with FT8. SSB is consistently 1200 watts output. Current draw is 20 to 25 amps on peaks.

    My documentation does not show a buck converter for the 13.8 volts. I see the current documents do have it shown. It must be an updated design. My 2 meter KW unit has one built in, but not the HF-6. I have a 30 amp 13.8 supply for all the low voltage stuff on my desk and I added the eb104 amp 13.8 connection. I bought a buck converter (Amazon) but have not gotten around to installing it. The bench supply works fine. The first one I tried was the switching supply for my Kenwood rig (PS-52) but the PWM circuit generates noise that gets onto the transmitted RF. It took some time to figure out the problem. Make sure your 13.8 supply is clean.

    I love these amps. I have 3 of them now. HF-6, 2 meter KW and 432 500 watt.

  8. K0GWA

    K0GWA XML Subscriber QRZ Page

    Well have several modifications to my #B2400 it has been very stable.
    Changes :

    1. Updated to vacuum relays for switchover
    2. Added 28V supply for vacuum relays.
    3. Replaced MRF1K50's with MRFX1K80's when the 1K50's smoked.
    Still to do.

    1. Add W6PQL ALC board
    2. replace 60 degree temp sensors with 75 degree.
    3. Readjust internal SWR circuit to 4:1 ratio as mentioned by others on the EB2400 FB group.

    I run the amp 90% of the time on AM being driven by a Flex 6600M. Easily does 1200W peak on AM voice peaks with 5 watts of drive and 150% modulation.
    100W drive, easily puts out 2500W key down.

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