You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
So I'm finished with this amp... I ended up putting the original transistors back and have about 60 watts out, whatever its enough. I did have one issue I didn't notice until I put the amp on the antenna. My relay was staying latched on after I was done keying. So simple fix was putting a 100k...
I think the kl203 is really an AB amp since it has the push pull topology, right?
Just checked dave made amps.... maaaaaybe going to try making my own first
Yeah I need to get some variable caps, I dont have any.
This radio is stock not that it matters.
I think I may start looking at other amps / making one. Any favorites that you guys have? I do not want anything crazy 100ish watts is plenty. I'm more concerned with clean and reliable signals...
I think I'm about to give up on this thing. I tried different cap values on C13 & C10... From nothing to 100pF-360pF. No major difference, but slight output power changes. then I went to R2 and put the 10k pot in there set to 10k and holy hell it went up to 70 watts! The thing is when i talk on...
Yeah thanks everyone for the input, I really appreciate it!.
So my results are similar to what miketa_us said. Going off my radio SWR meter, the SWR is terrible right now with these fets. I think I may play around with different values of C13 and C10. My reasoning being that the fets threw the...
It looks to me that R2=10k and R3=3.3k are a voltage divider for the bias circuit and the output is set to about 1.86 Volts... The threshold voltage for the IRF520N is 2-4 volts. So im thinking that I can put a 10k pot in there and tweak it until I regain the power lost. What do you think?
Heeey I fixed it, and guess what it was. The freaking relay. I bought another one off digikey just in case because I saw another thread with the top blown off the relay. I replaced that first and i got 60 watts out (before was <2 watts). The funny thing is the relay ohmed out fine, the relay...
I got some IRF-520 sitting in a digikey cart for about $1 a piece so its still worth it for me. Maybe I'll get some extras and try building an amp of my own design.
I'm going to pull the fets and test them out of circuit.
How do you turn down the 980?
Ha they ground off all markings I checked.
Yeah I was just measuring voltage with the scope, 18 volts on AM.
Is there an error with the schematic? I tried redownloading it and i opened it fine, if thats what you meant.
Yeah I do need to do that... Not sure how to turn down the Uniden 980 tho
I agree with that, that's what I measured as well. I think the damage is done, but yes I'll be putting them back. I just wanted to rule out the clamping circuit
This forum does not allow a single user to have more than one username. If anyone wants to change their username contact an admin and it will be done. Multiple accounts belonging to the same member will be deleted without warning.