Al-1500 blower question

Discussion in 'Amateur Radio Amplifiers' started by KN4CTD, Jan 20, 2019.

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  1. KN4CTD

    KN4CTD Ham Member QRZ Page

  2. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    What... is your Spidey Sense tingling?

    KN4CTD likes this.
  3. KN4CTD

    KN4CTD Ham Member QRZ Page

    No tingling lol, but I’ve heard enough horror stories that I’m not getting my hands anywhere near anything that could possibly get hv onto or into it. I’m still leery using a hv probe even though I know it’s safe. I go by the both hands in your pocket rule!
  4. N7EKU

    N7EKU Ham Member QRZ Page


    With HV silicone insulated wire, DC would not be an issue. Induced RF would be something to be careful about, but amp experts could probably add good expertise here about that. I would get fingers anywhere near the tube. The wires can be extended out as far as you want. You could even put a socket on the back panel for it if you want. Another option would be to connect it to a battery, analog meter, and appropriate voltage divider and make yourself a temperature gauge.

    As mentioned, infrared measurement can be tricky. Blackening the area you want to measure helps a lot -- just a spot of flat back paint will do it. I've found the laser pointer feature to be not so helpful and I just move it around to find the highest temperature area.

    I totally agree with being very careful around HV!


  5. KN4CTD

    KN4CTD Ham Member QRZ Page

    Thanks for all the suggestions everyone. I’m giving up trying to measure temperature using this method. I might get some indication sticks and try it again one day. I painted the head of the bolt in the center black....still shows really low temperatures being driven by 100 watts and tuned for max output.
  6. KN4CTD

    KN4CTD Ham Member QRZ Page

    I have two spare tubes with coolers itll probably never really matter no more than I use it. I get more satisfaction from using the dual gi-46b amp I put together in that yokogawa chassis.
  7. KN4CTD

    KN4CTD Ham Member QRZ Page

    I checked the fan speed taps....I stated that I thought we had moved to the high speed tap but I’m wrong. According to the manual, it is on the medium tap. I’m gonna move it before I put the lid back on.
  8. KN4CTD

    KN4CTD Ham Member QRZ Page

    Moved the fan to high speed. It’s pretty loud like that but it should be moving more air now.
  9. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    What did you say?

    Can't hear you over the blower noise.:p
    KN4CTD likes this.

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