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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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Thread Tools |
26th Dec 2019, 12:26 pm | #1 |
Pentode
Join Date: Oct 2005
Location: South coast near Ringwood/Christchurch, Dorset, UK.
Posts: 230
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Wavetek 2407 Signal generator
My Wavetek 2407 signal generator is giving trouble.
My first problem was an MRF571 driver transistor went short circuit for which I found an exact replacement but then the output transistor went the same way. I suspected tin whiskers so connected a PSU (reversed) across the emitter-base and removed the short which restored its operation. I now think its happened again as the RF output goes off and on intermittently. Sometimes the RF goes off long enough for an error message to be displayed before going back on. The device is an expensive MRF839F so I've ordered a similar shaped but cheap TP3034, but has anyone come across this sort of problem with early Motorola UHF transistors? It seems these may suffer from similar trouble to the Mullard transistors used in Roberts radios. Allan |
26th Dec 2019, 12:30 pm | #2 |
Dekatron
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
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Re: Wavetek 2407 Signal generator
Not seen it on those. I did have a couple of genuine MRF237s in a large batch that were DOA with shorts though but they are TO39 packaged. They were 1970s date coded. Can’t remember which end of the 70s.
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