drake tr4 problem no receive or out put

Discussion in '"Boat Anchor" & Classic Equipment' started by KI4OVR, Apr 4, 2012.

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  1. KI4OVR

    KI4OVR Ham Member QRZ Page

    I've got a tr4 all the tubes light up but oa2 has no sound and won't key, any body had this before, I've ordered a new oa2 tube.
     
  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    OA2 had no sound? It's a voltage regulator, it's not supposed to have any sound. It's supposed to glow blue or purple.

    I was a Drake authorized repair center for years when that rig was new in the late 1960s. Need a LOT more information to try to figure out what your problem might be.

    The OA2 has no "filament," and is not supposed to glow like regular tubes. But it should show some blue or purple color inside if it's getting bias and working.
     
  3. KI4OVR

    KI4OVR Ham Member QRZ Page

    When I say sound I'm talking about receive sounds out the speaker I checked that its good , oa2 is not getting warm at all or glowing at all. check filament fuse lamp at relay, it will not key with mic or paddle.
     
  4. KI4OVR

    KI4OVR Ham Member QRZ Page

    also if oa2 is bad will that effect receive and transmit.
     
  5. KO6WB

    KO6WB Premium Subscriber QRZ Page

    No it won't, It sounds like you need to check if you have any voltage aside from filament being supplied to the TR4. You will need a DVM and you also need to know what to look for. There are voltages in the power supply that can be fatal. It might be a very good idea to get some help from an amateur that has experience with tube type gear. Be very careful and follow standard safety practices.
    Again, there are voltages in the power supply that will kill you.
    Hope this helps
    73
    Gary
     
  6. KI4OVR

    KI4OVR Ham Member QRZ Page

    I've worked high voltages I'm a electrician but were do I check and what should I be looking for.
    I'll be very careful, I know what dc can do to you.
    73s ki4ovr
     
  7. KA4DPO

    KA4DPO Ham Member QRZ Page

    The OA2 is the regulator for the HF Oscillator, the VFO. If you don't have any voltage to the oscillator it won't work and you will have no transmit or receive. When you replace the tube make certain that all of the resistors in the regulator circuit are good before you power it up.
     
  8. W9GB

    W9GB Ham Member QRZ Page

    Manual highly recommended.
    http://www.wb4hfn.com/DRAKE/DrakeManuals.htm

    Treat like any High Voltage appliance, when plugged in and energized.
    You will need DVM probes at specific socket pins or terminal points or strips.

    Relay care for Drake TR-4
    http://www.wb4hfn.com/DRAKE/DrakeArticles/TechTips/RelayCare.htm

    Troubleshooting Antenna Relay Problems
    http://www.wb4hfn.com/DRAKE/DrakeArticles/TechTips/TroubleshootingAntRealy.htm

    w9gb
     
    Last edited: Apr 4, 2012
  9. KI4OVR

    KI4OVR Ham Member QRZ Page

    I've got a copy of the manual, and a meter the schematic on the ac 3 shows the voltage I should have, and I noticed one reply said a bad oa2 tube bad would keep the radio from receive and transmit and one said it wouldn't. If any one else can help in that area it would be appreciated, been to wb4hfn site and have contacted him it might end up there.
    73s ki4ovr
     
  10. KI4OVR

    KI4OVR Ham Member QRZ Page

    Thanks for all the help guys traced it down to power supply, going to get rebuild kit http://www.sunlightenergysystems.com/theheathkitshop/page7/page7.html
    73s ki4ovr
     
  11. W9GB

    W9GB Ham Member QRZ Page

    Terry -

    Great. After 40 years, it is not surprising that these HV components are failing.
    High Voltage (HV) electrolytic capacitors have a specific operating life. CDE/Mallory actually states this expected life with their product specifications.

    Mike Bryce, WB8VGE has a nice Drake AC-3/AC-4 replacement board and the instructions.
    When used with the Drake schematics it is a straight forward replacment with a bit of soldering involved.
    Since these leads are HV, be patient and make good solder joints !!
    http://www.sunlightenergysystems.com/theheathkitshop/page2/page2.html
    ==
    w9gb
     
  12. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    The the 0A2: These "almost" never fail. The only thing that takes them out is physical breakage of the glass, or the series resistor drifting down so low in value that there's too much current igniting the tube.

    But if it doesn't glow, chances are there's no voltage getting to it and if so then of course the PTO won't work and the rig cannot possibly receive or transmit.
     
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