Dentron amplifier -is this explanation real?

Discussion in 'Amateur Radio Amplifiers' started by K1OIK, Nov 22, 2019.

ad: L-HROutlet
ad: l-rl
ad: abrind-2
ad: L-MFJ
ad: Subscribe
ad: Left-3
ad: QSOToday-1
ad: Left-2
  1. K1OIK

    K1OIK Platinum Subscriber Platinum Subscriber QRZ Page

    I have an amplifier that has low output primarily to line voltage that drops to under 100 volts under load.
    I received this comment of advice/explanation whose name I withhold.
    It does not seem accurate to me.
    Your opinion.

    "I looked up the 8 caps in the hv power supply for the cliperton l.
    They should have a rating of 100pf at 500 volts..
    These caps act as a filter/voltage stabilizer for the power. When the amp is powered on they will create a 4000 volt reservoir for the amp to pull from. When the amp is under load on ssb and the peak power RF output is 1kw..your voltage gets pulled through these caps.
    If you drop the capacity to 400 volts per cap at 100pf then the reservoir drops to only 3200 volts to pull from.
    It will not blow up the will have a very weak RF amp .
    That is why I said check the ratings on the replacement caps.. to make sure they were correct.
    You indicated you have lower power output than you should"
  2. KB7WG

    KB7WG Ham Member QRZ Page

    Have you a print? The amount a capacitance in the filter will not affect input voltage.

    It's a charge reservoir, not a voltage reservoir.

    Pull the rectifier and check voltage.

    I believe I asked you what the voltage was at toaster oven outlet.
  3. WA5VGO

    WA5VGO Ham Member QRZ Page

    That is ridiculous.
    AI3V, N0TZU, K1OIK and 2 others like this.
  4. G0JUR

    G0JUR Ham Member QRZ Page

    Gibberish, the voltage rating of the capacitors rates the voltage they will withstand b4 pop goes the weasel.
    N0TZU and K1OIK like this.
  5. KP4SX

    KP4SX Premium Subscriber QRZ Page

    Especially those 100pf ones.
    W1BR, KC1KWX, WA7PRC and 3 others like this.
  6. G0JUR

    G0JUR Ham Member QRZ Page

    I let that bit go..didnt want to tax the brain cells of some readers :p
    K1OIK likes this.
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    The 100pF caps work perfectly in a switchmode power supply with a switching frequency of >400 MHz.

    I didn't think the Dentron had that...:rolleyes:
    W1BR, WA7PRC, K1OIK and 1 other person like this.
  8. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I had a Clipperton-L about 38 years ago or so and I'm surprised it does much of anything at 100V.

    I used mine on 240V only and it worked very well!
    WA7PRC and N2EY like this.
  9. WR2E

    WR2E Ham Member QRZ Page

    If your voltage is sagging to 100 under load you had better get an electrician out there STAT!

    I would not expect more than 3% voltage sag at the outlet at full load.

    If you’re seeing more than that there’s a loose connection somewhere. Loose connections mean HEAT. Heat leads to FIRE!
    Last edited: Nov 22, 2019
    W1BR, N0TZU, WA7PRC and 2 others like this.
  10. N2EY

    N2EY XML Subscriber QRZ Page

    Stop right there!

    If the line voltage drops to 100 volts from the nominal 120 volts under load, something else is very wrong and the amplifier should never be operated that way.

    You have been notified.

    You should know better.
    WQ4G, N0TZU, AF7XT and 2 others like this.

Share This Page