Delay Too Long

[HomerBB]

I have picked up this little 100 watt amp. I don't know the brand as all it has on it is 10 Meter Linear Amplifier. What I do know is it works well but for one thing - the relays hold too long after releasing the key. Is there a fix for this? perhaps a diode change, etc?

Thanks.

 

[Toll_Free]

I have picked up this little 100 watt amp. I don't know the brand as all it has on it is 10 Meter Linear Amplifier. What I do know is it works well but for one thing - the relays hold too long after releasing the key. Is there a fix for this? perhaps a diode change, etc?

Thanks.

Check the two electrolytics in the amplifier.

Your bottom pic, the krzci one, has a small cap on the bottom rt of the amp board... I'd be willing to bet that's the delay cap.... Remove it, and it should kill ALL the delay. Also, I'd guess the jumper next to it would be the way to remove all.

Change the value of the cap, and it should change the delay. More uF will be more delay. Less uF, less delay.

If that cap doesn't do it, it would be the electrolytic next to the power wire / fuse / etc. I doubt it's that one, though, since you should have at least ONE electrolytic across the input leads to filter RF out of the power leads.

Nice chinese designed boards... I have a Palomar 300HD with a VERY similiar board in it.... Mine actually has two traces on the front of the board to add a switch to so you can put SSB/AM switch in, if desired.

This whole "Auto SSB" thing was a fucking gimmic in the first place, so they could cheap out and save the cost of a switch, adding 10 dollars to the wholesale cost of the amp for the "auto" feature.

--Toll_Free

 

[HomerBB]

I'll try the cut the jumper piece and see what happens. If that works perhaps I can lower the cap and put a SSB switch in line there.

Thanks.

 

[HomerBB]

Your answer was just what I needed to get me on the right track. The capacitor you pointed out was the right one. first I removed it and all delay was removed, but clickety on sideband. Noticing the VR next to the cap I decided to put it back in and try the variable. It worked. Now I have engagement on sideband and quick release on AM.

Thanks a million, Toll Free

 

[TonyV225]

I remember the first run of the blue face Palomar 225 Amplifiers did this real bad and you could get rid of the delay by clipping a leg on an Electrolytic capacitor but then SSB was not usable due to the dreaded chatter.

 

[HomerBB]

Yep. Exactly what I experienced. If not for it having the variable in it i would have had to change either the cap or a resistor to get it where I needed it.