single mosfet dx 959 to dual mosfet dx 959

[montecarlossfan]

I just converted my dx 959 single mosfet to dual mosfet and am still getting the ame numbers, i still cannot get more than a 5w deadkey..i was able to with the single mosfet then one day it wouldnt go above 5 watts deadey with adjusting the hi output power pot. It swings no more than 18-20watts is there something else wrong ..i looked at a dx 2517 schematic and verified all parts and installed the dual finals I can set bias according to the dx2517 manual also and still do not get the numbers out of it...is it possible there is an issue elesewhere in the radio?

Thats what i was thinking because it will not do the numbers i think it can and have seen.. I am a 3rd year electronics engineering student and i may just be overlookin something here. ''I also had a nice 30w pep on single final then it would only do 20watts and didnt make a difference..both parts are working to output the carrier and such...they all get warm

[petriach]

You'll probably want to upgrade the power transistor,also(2SB754,Q54). I don't know if that's the issue,but it might be.

I know on my 949 when my output approaches 20W+,the lights dim really bad. Is there a way you can check the voltages? It may just be too starved for power.

[montecarlossfan]

it has the new updated part in it...it used to deadkey 8w max with single final then one day that gave the ghost and 5 was all it would do...still same position

[TheCBDoctor]

Hi montecarlossfan

You will get the same numbers because you are not amplifying any more than before. It would be like putting 2 nine volt batteries in parallel; you will still get 9 volts, but twice the current capability. If you put the two nine volt batteries in series then you would get 18 volts. Two finals would in parallel would be the same in theory.

The 2 finals must be tied together using a toroidal coil. Check any radio with dual finals and see what they did differently.

Respectfully,

[montecarlossfan]

I matched the schematic of a dx2517.........I would think they designed that radio to do more than 18w pep....Maybe I am missing something here....Is it the fact that they use 1k resistors instead of coils to tie them together? I may just convert it the erf2030 kit way with a fix for the error on that conversion sheet.....

Hmm Im missing d93 labeled as X lol

but according to the parts list on the 2517 its a 1n4148...

[montecarlossfan]

i got it all figured out...2 caps had to be romoved ...duhhh! lol

[TheCBDoctor]

Hi montecarlossfan,

i got it all figured out...2 caps had to be romoved ...duhhh! lol

Sometimes it is that simple...............

It happens. I have had radios that broke my chops for a week or more only to wake up one day and realized what I was doing wrong and fix it in 5 minutes. When you start repairing radios in your sleep it is time to take a break for a while.

Respectfully,

[xracerx13]

i got it all figured out...2 caps had to be romoved ...duhhh! lol

A very old post but I am trying to revive it in the hope to find out which 2 caps you speak of that you removed.

My situation was sort of similar but I am working with a Dx959 with 2sc1969 finals.
It originally came with a 2166 driving a single 1969.
I replaced everything that was missing for the extra final section and I am only getting 13w rms bird and 35 PEP.
Correct biasing was done and upgraded the supply caps, and Q54 to a 2sb817, and the following:
Remove C218 (3pf)
Change C216 (470pf) to a 1000pf (100V mylar-type)
Remove C210 (470pf)
Remove C199 (560pf) and reinstall it in the C210 spot.

L35 is a 7 turn coil. and on the 2517 it has a 4 turn coil found in the driver area. Could this also be a reason that I am not seeing a bigger output?

Madmax
231WNY