Radio valve problem ?

  1. angellonewolf

    angellonewolf Member

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    if you cant do it im way over my know how
     
  2. Blackolive

    Blackolive Member

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    uk lancs
    :clapping::clapping::clapping: “thread closed”:scared:
     
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  3. angellonewolf

    angellonewolf Member

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    what type of capactors are these on here

    the new type capactors are lightly to be a lot smaller ?
     
  4. I think that the readers of this group may be under the impression that your reply was a joke. How little they appreciate the moderation here. :D
     
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  5. rtbcomp

    rtbcomp Moderator Staff Member

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    Yes, modern caps, especially electrolytics, are much smaller than the old ones. Just make sure the voltage rating of the replacements is the same or greater than the originals.
     
  6. rtbcomp

    rtbcomp Moderator Staff Member

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    Before

    DSCN2346 Crop Small.jpg

    After

    DSCN2362 Small.jpg
     
  7. angellonewolf

    angellonewolf Member

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    on this pic what ones would i be looking at replacing [​IMG]
     
  8. rtbcomp

    rtbcomp Moderator Staff Member

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    Those aluminium cylinders on the top left and the orange one to the right.

    The ally ones may be dual capacitors, ie 2 caps in the same casing. The guts can be removed and a couple of modern caps fitted inside the original tube.

    DSCN2365 Small.jpg DSCN2367 Small.jpg DSCN2369 Small.jpg DSCN2375 Small.jpg
     
  9. angellonewolf

    angellonewolf Member

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    what about the metal cylinder under the orange one is that one as well

    and would the values be the same for both capactors in the metal tube ?
     
  10. rtbcomp

    rtbcomp Moderator Staff Member

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    ^^ It doesn't look like an electrolytic, but no harm in checking/changing.

    Multiple caps in the same tube aren't necessarily the same. The valeus should be printed on the side, the connectors may be colour coded.
     
  11. angellonewolf

    angellonewolf Member

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    love the may be
     
  12. eddie49 Member

    Thanks for clarifying the 3 black wires. They are for connecting to the aerial, which is a flat coil of wire in the lid of the radio cabinet.
    Before worrying about capacitors, I would suggest, as Windy Miller and RonA have said, that step 1 should be to get all the valve heaters glowing, and step 2 should be to confirm that HT ( 90v DC ) is present.
    With power off, carefully unplug each valve, one-at-a-time. Note what is written on the valve ( such as: DL96, DAF96, DF96, DK96, etc. ), then re-insert the valve fully. Do this to all the valves, then power up and check again if all the heaters are glowing. Once we know what type the valves are, we can check the pins for heater continuity and HT voltage ( courtesy of my Iliffe Books Ltd."Radio Valve Data", first published Feb.1949 ).
     
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  13. angellonewolf

    angellonewolf Member

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    got to help a mate tonight but will try to have a look tonight at the values of the caps
     
  14. Just to add, be careful where you stick your digits! The mains side of equipment like that was generally not buried under lots of covers and insulation.

    If you have a look on the following site, you may be able to get a service sheet for it. That will show you where and what voltages to expect etc. https://www.service-data.com/
     
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  15. angellonewolf

    angellonewolf Member

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    ^^^^ i was well aware of that as i was trying to manhandle it around it would be nice to dismantle it fully out of the case so will look at that first or i will breke a cable making it unuseable
     
  16. eddie49 Member

    I've edited my post number 32 above, to suggest re-inserting the valves, in case the pin connections are loose or corroded.
     
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  17. rtbcomp

    rtbcomp Moderator Staff Member

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    Bear in mind the DC HT could be present on various capacitors for some time after switching off, also it's not always easy to see the heaters on some valves.

    The site mentioned by ajl in post #2 sells manuals and service sheets in PDF format.
     
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  18. angellonewolf

    angellonewolf Member

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    the 3 in line on 1 side look to bea easy to remove the one thats lighting up i cant seam to remove it is there a locking pin ?
     
  19. angellonewolf

    angellonewolf Member

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    thanks for the heads up i know about power hanging around after power down thats why there was static aafter it was unpluged
     
  20. eddie49 Member

    It does look like the base of the valve that is lit up has got two spring locking tabs that engage with the valve. They will probably be type B7G valve bases.
    I was not aware that this type had locks - but since this one valve lights up OK, I guess it can stay in place.
    The base has 7 pins arranged in a circle, with a gap to provide correct location. The filament ( heater ) pins are 1 and 7, across the gap. There should be continuity from 1 to 7 , maybe from 5 to about 50 Ohms resistance.
     
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