Magnum s9 rough ssb tx audio.

[listner132]

hi guys a posted about 2 weeks ago that my mate was selling the above radio with an astatic silver eagle mic..well after some though i decided to buy them both for £150 and to my surprise he threw in a nice old turner expander 500 desk mic..now everything works fine with the s9 apart from the ssb tx audio seems to be a tad rough like using a burner/linear. Power output on ssb is fine around 45 too 50w pep. Any ideas what migh be wrong ? i am using the standard magnum mic and i have tried on both mic sockets..still the same. I have read some stuff on the net that this might be a common problem with this type of radio..please help as this is a lovley radio.

thanks.

[cb4ever104]

Possible bias issue ? Aren't there 2 versions of this radio . One with 2312 and the other with mosfet finals ? Anyway. I'd give the final stage a once over to see what's what.

[listner132]

thanks again fella..think the output stage is erf2030 x 3 1 is for driver also.

[dt307]

http://cbtricks.com/radios/rflimited/ma ... ns_adj.htm

all the info here and there is a link in the top left corner for the locations

i norm set mosfets via voltage not current but hey magnum built it they should know

[cb4ever104]

i norm set mosfets via voltage not current but hey magnum built it they should know

I don't have any mosfet radios , so I've no idea how to set them

[dt307]

i norm set mosfets via voltage not current but hey magnum built it they should know

I don't have any mosfet radios , so I've no idea how to set them

when they start to smoke ....back it off a little and your good to go

[dt307]

had two mrf477 die in last 2 days ...not happy and no idea why .....strange

[listner132]

I will check gate voltage it should be round about 3.2 volts.

[dt307]

3.7 v i norm set them at