English Channel HELP !!!!

Started by MartyMart, September 14, 2004, 05:41:25 AM

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MartyMart

OK, i have a problem with Q2 which is giving me "splatty" and mostly no output from the build, so . . . .
First changed the J201 at Q2 4 times...... no no still get more than 7v at the drain.......
Re wired the whole of the Q2 circuit area and replaced both 470pf and 100pf caps which go to the vol pot.
No better ???
Now I'm stumped, if i touch the back of the board around Q2 ( hence grounding it? )  then i get some nice sounding drive for a few seconds which quickly becomes "splatty" again !

Any Ideas?  Ricky ?
The build was slow and careful with very high quality parts/wire so i can't understand the constant problem  :?

Thanks,
Marty.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

RDV

Do you mean .7v instead of 7v ?, cause 7v would be real high. Do you mean you can't get it any lower than 7v?

RDV

MartyMart

Thanks and Hi  Ricky, yeah i can't get a reading less than 7.2v from Q2's drain which should be more like 4.5v !!
Any thoughts ?
Q3 is a little screwed because of Q2, but 1, 4 and 5 are fine
Thanks,
Marty.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

RDV

I know this is an obvious sort of thing, but are sure of the value of the trimpot on Q2. Make sure it's a 100k.

RDV

MartyMart

I know, i've been over the obvious stuff about three times, just to make sure !  all is as it should be and i can't see a "ground" that i've missed, which is what my gut feeling is.
When i ground the back of the circuit at Q2, it almost works !!
perhaps i should change all the components and the 100kpot around Q2?

rrrrrrrrggggghhhhh !!!

Marty.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com