dx949 and kl503 issues on ssb

[hammer0630]

I have the exact same amp and two KL-203's they all work fine I never got any chatter from the relay on my 503 used as a base station with a 148GTL I have extremely loud audio and my radio on am sits at 2db carrier and swings to 15 watts and on SSB 0 to 18 watts you maybe are not driving it enough and keying up with out talking is bound to cause the relays to bounce on and off and you may not beware of the actual mechanical movement of the mic key up switch will be picked up as audio and you will see the radio and anything inline responding to the audio and the increase of wattage. I did watch your video and my KL-503 does not operate like yours but it's just a tiny glimpse of whats going on there but when talking SSB keep your audio up and when you key up be ready to talk should help.

 

[Mudfoot]

I have that same amp as well, plus 3 other RM amps. None of them act like that.

 

[mustang_gt_350]

i think im going to put a meter on it and see if either the mic is causing a problem when its keyed, or if maybe its putting out a slight amount of power when it is keyed up when it shouldnt be. i found a post in another forum where somone had this problem and they said it was actually trasmitting a slight "carrier" when it was keyed on ssb and it was causing a amp issue the same as mine. i believe they said they had to turn down the VR6 pot.

 

[mustang_gt_350]

I put the cheap power meter i have on my radio. when on ssb and i key the needle jumps up about .25ish watts then drops back to zero. Im not sure if its a mic click causing that or if its something else.

 

[JoeDirt]

I have a KL503 relay clicks over with vary little watts. Mine doesn't like SSB it acts as of the relay is chattering but its not. The only way I could get it to work is with the ALC all the way up and just about yell into the microphone.

 

[JoeDirt]

I haven't had time to track the problem down but I will post my findings.

 

[mustang_gt_350]

Ok i did some fiddling with it today. I wanted to somwhat calibrat the rf meter and turn down the low end of AM and adjust the high end. Anyway, i noticed on ssb when i would key up there was a slight amount of RF showing on my 0-5w meter. So i just tweaked the VR6 "SSB Carrier Balance" a little on my dx949 to where when i would key up there was no difference between keyed and unkeyed on the watt meter. I just tossed the radio back into the jeep and now when i have it on SSB and key up the TX light doesn't light on the radio and the relay doesn't chatter. So i can key up, speak the relay closes and i can speak as normal and then unkey the mic and do it all over again. I beleive i have it figured out. I just have to find somone nearby that can run LSB with me to see how it sounds.

The band is open, but i can't reach anyone

 

[JoeDirt]

Here is what I did to fix my RM KL503, I think RM Italy had some out of spec caps because C34 was not providing enough bias to the base of TR2. Allowing the the main RX/TX relay to still be keyed because of the SSB delay but not all they relays in the amp would stay keyed for the low rf levels in between your speech.

Add 10pf-15pf cap across C34 like this

 

[BJB]

A little off topic but I am interested in these amps, but have been warned off with purists indicating that they deliver a lot of splatter into other channels, upset the neighbours..etc...Is this the case.

If some of these amps act up then is it worth taking a chance with them. Some don't have a problem others think they're crap. I was thinking of running an old Uniden Grant with one of these in the car . Car alternator puts out 35 amps.

Love the concept of these amps...just ???

 

[undertaker]

I have the KL203 on my grant and it works flawlessly....

 

[AL567]

A little off topic but I am interested in these amps, but have been warned off with purists indicating that they deliver a lot of splatter into other channels, upset the neighbours..etc...Is this the case.

If some of these amps act up then is it worth taking a chance with them. Some don't have a problem others think they're crap. I was thinking of running an old Uniden Grant with one of these in the car . Car alternator puts out 35 amps.

Love the concept of these amps...just ???

I've Never had any problems with 503 nor any complaints from the neighbors and I live in a crowded neighborhood. Now I had some ssb issues when I had the 200p but none at all with the 503.

 

[Mikey1966]

You can change the value of a resistor in there to extend or shorten the time of the delay. Not sure which one though in a KL amplifier. I too had a KL203 that would act this way, for what I had in it I just left it.

Not resistor, capacitor. 3.3uf

 

[Mikey1966]

I have that same amp as well, plus 3 other RM amps. None of them act like that.

My delay on my kl503HD is too long. It has a 3.3uf cap. I did do away with the driver transistor. The long delay was long both ways so taking driver out didn’t do it. Now with just 8 finals it sounds perfect on ssb. With that driver it sounded bad. I want to change the capacitor from 3.3uf to a 2 or 2.5uf to shorten it but I don’t want to tear it down again.

 

[nomadradio]

My advice for this issue is to wire the "morse code key" jack so that a foot switch or hand switch keys the Texas Star.

Kinda clumsy, needing one hand for the mike and one for the linear. Putting a relay inside the radio will make it into a real "ham" radio by plugging a patch cord into the jack for the radio's new relay, and the other end of the patch cord into the Texas Star's keying socket.

No more chatter. No more delay. No more opening the cabinet to tweak the delay capacitor.

73