Cobra 29 IRF520 install Question
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WIRADIOOP
- 4 PILL USER
- Posts: 30
- Joined: November 21st, 2012, 7:34 pm
Cobra 29 IRF520 install Question
Hello fellow CB radio operators. I received a cobra 29 with the irf520 final. The radio was needing repair and I'm not real familiar with with this final upgrade. I have seem many online resources for the install. The question I have is this one does not have the companion components that are referenced in the installs I've seen. It does however have diode soldered between the gate and source. Is this a standard switching diode or a zener? I cannot make out any identification on the component. I'm just interested in understanding this circuit modification. If anyone has done this mod and can shed some light on the diode component I would be very grateful. Thanks for your time and good DX. Maybe I'll hear some of you in WI!
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Slowdraw
- Donor
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- Joined: March 17th, 2007, 8:32 am
When I use an IRF520, I will sometimes use a 40 volt zener diode like that to prevent voltage spikes from momentary high SWR to protect the mosfet. The IRF520 has a 50 volt breakdown voltage. If you use an IRF521, it is not necessary as that mosfet has a 100 volt breakdown rating.
