| Author |
Message |
    
Adshar64
| | Posted on Friday, August 08, 2003 - 5:34 am: | 
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Just got a Zetagi bv2001 tube amp ie 4 X el509's. Anyhow guy who sold it to me said it works but it doesnt, and Ive done my money. On key up the relay chatters like heck with arcing at points. transformer is pulling plenty of amps ,but there is no amplification. Any ideas? does this sound like a typical fault?
cheers Adrian |
Allagator
| | Posted on Friday, August 08, 2003 - 7:24 pm: |
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Sounds like you need to turn the power up on the radio !!!! but you mite ask a real teck !!!!
Allagator |
Adshar64
| | Posted on Saturday, August 09, 2003 - 2:45 am: |
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I checked it out and filter caps are all shorted, so on the road to repair. I was looking for a quick review before I checked it out as some faults are typical. Crocadiles make allagators look stupid anytime lol. |
Highlander
| | Posted on Saturday, August 09, 2003 - 9:45 am: |
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Make sure all your jumpers and coax connectors (PL259s) are soldered correctly, try a different length jumper between radio and amp *--flame sheilds up--* (it really does help sometimes)
Try turning on the SSB delay if it has one. Make sure SWR is ok, set radio carrier to 2 watt or less. |
Adshar64
| | Posted on Saturday, August 09, 2003 - 4:10 pm: |
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Thanks Highlander, Yes well as you can see in the post before yours I have checked out the problem and found the cause. A underdrive problem wouldnt cause the transformer loading and arcing I was getting. When I thought about it I expected a capacitor problem and thats what it was. Three 350v 150 uf caps all internally shorted, explaining the heavy transformer load and arcing at relay etc. Will replace with 500v caps and things should be fine. I'm fairly self sufficient in solidstate gear and this was my first tube amp so was lookin for advice from the "tube guys" lol.Tube stuff is quite interesting when you get into them, doing some upgrade study with a good book I've found. ie "The Radio Handbook" which covers tube amps nicely. BTW all good advice there thx. |
Adshar64
| | Posted on Friday, August 29, 2003 - 5:12 pm: |
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Ended up fitting 450v 160 uf caps to this from rfparts and works a treat.Beefed up some input resistors to 6w rating to handle ~30 w pep ssb drive and is peaking 1.5 kw. Limited by the transformer. Not bad for el509's
one driving three. |
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