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  1. #1

    Tokyo Hy-Power 2.5KFX info

    I just picked up a tech special Tokyo Hy-Power 2.5KFX on ebay for a song but the current schematic is the old one not the newer one
    looks like mine is a 2012 version. solid copper heat sync firmware 1.5E

    does anyone have a manual with a schematic or better yet a service manual ???

    so far I got a PROT FUSE error fuses are good main pa relay is not engaging, no ground to coil. tracing the circuit back to cpu board JP16 from the schematic D14 is a 1N4007 , on the board it is D16 a ZNR V10270. best guess I think the IS04 solid state relay needs to be replaced. schematic says AQV205 actual part is a AQZ205D.

    I am sure this is only one of many problems with this one but I am sure I will get it going again

    any documentation help would be great


    thanks all

    Bruce

  2. #2
    Active User Contributing Member KD8MJR's Avatar
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    Bruce that error sounds like the fuses that feed the mosfets are blown. They are under a metal cover just before the PA board and supply the 100Vdc to the Mosfets. More importantly the Mosfets themselves may be blown and you need to know that before replacing the fuses or you will make matters a lot worst.
    If you check the mosfets and it's a Drain to Source are shorted then you are in luck. A simple replacement and some checks should do the trick. If it is a Drain to Gate short you are going to have your work cutout for you. The voltage throug the gate will most likely have killed the Bias circuit and possibly the Fan control circuit.
    You will have to rebuild the bias circuits on both sides including replacing the temperature monitor and the three adjustment trim pots, replace the ceramic capacitors on either side of the bias trace and then replace the mosfets and when everything is fixed, you bypass the power supply and use a current limited bench supply at 24VDC at about 500ma maximum and see if the mosfets are not shorting or doing anything strange. Once that is determined you can slowly bring up the bias on each side to 200ma just to see that everything is ok and then go back to zero.
    Next you would need to hookup the 100vdc supply through two amp meters and then slowly adjust the Bias levels to 500ma per mosfet. When that is done you need a small gas torch to heat up the heatsink to around 45deg C while monitoring the Bias current. It will rise but you need to lower it back down with the Trim pots to a maximum of 500ma. After adjusting them I find the current to be about 350ma on a cool heatsink and 500ma at 50deg C.

    I know that's a lot of info condensed but that is the best I can offer. I assume you know how to fix amplifiers so you should be good to go.

    BTW the model you have might be the newer model. The 1.5E firmware was from the last models but they also did hardware changes. Some people got hold of the chips and just upgraded the firmware alone on older models. Mine is a 2013 model that went back to Japan for the Hardware upgrades just before they closed. If yours was sent back to Japan then it has all the upgrades.

    73
    Rob

  3. #3
    Hey Rob,

    Nice to see you've setup a wonderful forum for us lucky THP owners.

    I have a HL-2.5Kfx, with firmware 1.5D.

    Do you know how I could tell when it was made and/or whether or not it has the latest mods?

    I had a coax short due to not observing the bend radius (LMR-195, 5.0:1 SWR, Foam Dielectric) right after the Palstar HF Auto output and it went straight into protection just fine.

    The data sheet on the ARF-1500 Mosfets makes them look indestructible.

    In your opinion, which is the better amp? The HL-2.5Kfx or the HL-2500Kfx?

    73,

    Jarrad

  4. #4
    Active User Contributing Member KD8MJR's Avatar
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    Jarrad its a bit of a mixed answer. If 6M is not important than the 2.5Kfx is a better amplifier.
    It's massive solid copper heatsink and huge transformer make it more reliable and the power output can do 1800W easily and even peak to 2200W.
    The 2500FX uses aluminum heatsinks and should never be run above 1500W. It's dual switching power supplies cannot handle anything higher.
    Also the 2500fx is a larger amplifier than the 2.5Kfx. The one nice thing about the 2500FX is the 6M option.

    BTW ARF-1500 are not indestructible, I have seen them blow out. Never try to bypass the amplifiers high SWR safety circuit by running at reduced power into a high SWR antenna. In this case the owner was running at 300W into an antenna with 2.3 SWR. If he went any higher the amplifier would trip so he figured he was safe running at 300W. Well after 10 minutes the ARF-1500's could endure no more and they burned out. Worst part was that they shorted voltage to the gate and hit put the Bias circuit and a few other sections of the board.

    Rob

  5. #5
    Active User Contributing Member KD8MJR's Avatar
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    Quote Originally Posted by W7PK View Post
    I just picked up a tech special Tokyo Hy-Power 2.5KFX on ebay for a song but the current schematic is the old one not the newer one
    looks like mine is a 2012 version. solid copper heat sync firmware 1.5E

    does anyone have a manual with a schematic or better yet a service manual ???

    so far I got a PROT FUSE error fuses are good main pa relay is not engaging, no ground to coil. tracing the circuit back to cpu board JP16 from the schematic D14 is a 1N4007 , on the board it is D16 a ZNR V10270. best guess I think the IS04 solid state relay needs to be replaced. schematic says AQV205 actual part is a AQZ205D.

    I am sure this is only one of many problems with this one but I am sure I will get it going again

    any documentation help would be great


    thanks all

    Bruce
    Sorry Bruce their is no service manual.
    I would imagine by now you got the problem resolved. What was wrong with the amp?

    Rob

  6. #6
    Quote Originally Posted by KD8MJR View Post
    Jarrad its a bit of a mixed answer. If 6M is not important than the 2.5Kfx is a better amplifier.
    It's massive solid copper heatsink and huge transformer make it more reliable and the power output can do 1800W easily and even peak to 2200W.
    The 2500FX uses aluminum heatsinks and should never be run above 1500W. It's dual switching power supplies cannot handle anything higher.
    Also the 2500fx is a larger amplifier than the 2.5Kfx. The one nice thing about the 2500FX is the 6M option.

    BTW ARF-1500 are not indestructible, I have seen them blow out. Never try to bypass the amplifiers high SWR safety circuit by running at reduced power into a high SWR antenna. In this case the owner was running at 300W into an antenna with 2.3 SWR. If he went any higher the amplifier would trip so he figured he was safe running at 300W. Well after 10 minutes the ARF-1500's could endure no more and they burned out. Worst part was that they shorted voltage to the gate and hit put the Bias circuit and a few other sections of the board.

    Rob
    Dear Rob,

    Unfortunately whilst running digital modes at moderate power my station suffered a catastrophic failure. The first sign of failure was my 40A 13.8v rail went into protection, powering off most all of the shack (including the Palstar HF-AUTO ATU, which features non latching relays).

    Upon powering back up, I decided to try the exciter first before using the amp. My exciter put out no power, even in RTTY / FM. On 6M into a dummy load, it registered about 2 watts, indicating the drivers seemed to be intact but the PA was toast.

    My spare IC-7200 was then hooked up. Naturally, it put out enough carrier to tune the ATU. I then power cycled the amp, and put it in operate, only to receive what I would learn was the most dreaded message possible: PROT FUSE-BLOW.

    Reading the manual it suggested I replace to internal fuses. Once I had located them and replaced them, I powered the amp up on the workbench. As soon as I switched it into operate, their was an arc and the fuses blew again. Next time, I disconnected the final board B+ rail, and the amp switched into operate just fine.

    I'm not sure what caused the issue. I was running the new FT8 digital mode which features a 13 on 17 off, below 50% duty cycle. I cannot be sure, but I suspect the exciter failed, causing the 12V rail to go into protect, and the considerable tank circuit energy of the HF-AUTO (which dropped its relay to the antenna) to collapse into the finals of the HL-2.5Kfx. Thats my best guess at this point.

    The amplifier is now with an experienced commercial tech, with a 'save no costs' order. In the meanwhile I picked up a NEW IN BOX HL-450B to keep me from suffering QRP.

    I have run digital modes with amplifiers successfully for years, so this recent failure was unprecedented. My only hunch is that something about the FT-8 mode (which didn't exist when the IC-7300 was made) caused its PA to fail. It could of just been chance.

    In future, my Palstar HF-AUTO will run on its own power rail... thats a certainty....
    Last edited by vk3bl; 08-21-2017 at 04:15 AM.

  7. #7
    Active User Contributing Member KD8MJR's Avatar
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    Jarrad sorry to hear about your loss. I have repaired one that had a similar failure. The fuses were replaced without checking the finals, if it had been checked the operator would have seen that the source and drain were completely shorted. It seems like if you just replace the fuse the source to gate then gets shorted and the full 100Vdc ends up in the bias circuit. Luckily this amp did not have any destroyed traces but the finals needed replacing along with most of the Bias components including the bias pots and some other diodes and small caps.

    It's a pretty nerve racking experience after you do the repair because the finals are so expensive. Going from memory I think I used a variable bench supply and set it at 20VDC and a maximum of about 1amp and started testing from there. Re adjusting the bias was tricky because the voltage blew out the original Pots so I had to slowly adjust each one up a bit until everything was right. I then backed it off a bit and connected back the 100Vdc power supply and put in some low amperage fuses and slowly set the bias adjustment. tried some low power like 100W using a small amount of drive and then put in the right fuses and slowly bought up the power while monitoring the current.

    The good news is that the amp has worked flawlessly for the last 2 years and the parts where readily available.

    BTW in digital modes back the power down to 400 watts max. It's much safer and makes very little difference to the signal.

    Rob

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