pc66xl

[mugsy]

i need help i need to turn up the dead key on the radio . i dont know what slug i need to turn i know vr5 is modulation and then they say am power is L8 L9 L10 L13 but they are just littel copper coils and i cant find 13 i think its the one in the front with wax on it any one help me .. Or is there a varibl power mod i can do ? uniden pc66xl

[Tombstone (R.I.P.)]

L10, L9, L8, my books say nothing about L13. Be careful when turning the slugs in those transformers (coils). Use you soldering iron and heat the slugs a little and then turn them with a non conductive alignment tool, dont try and use a screwdriver or allen wrench, you'll have a good chance of breaking the slug and then you'll have problems. Power modification: Change R76 (2.2K) to a 1K, Change R43 (10 ohm) to a 2.7 ohm, Change R108 (1 ohm) to a .47 ohm. Then retune L13, L10, L9, L8. Now they mention L13 but it's not listed in the regular power tune up procedure. I don't advise doing power modifications since that's hard on components, if you need more power I suggest using an amplifier but you asked and to each his own, hope this helps you.

Tombstone

[mugsy]

yeh i have the ekl mosfets 2030 finals i got a new amp and they said to hit it with a 5watt dk and i was wondering how to turn those coils so i can get my dead key up and i was wondering if there is a variabl power mod i can do ?

[Tombstone (R.I.P.)]

I explained the proper method on how to peak the transformers and turn the slugs and described the power modification in my previous post. I'm not sure how to make the power variable or what to change to make the mosfets work.

Tombstone

[mugsy]

no im looking in the radio l10 has no slug in it but a plastic sleave and l8 and l9 are coils laying on there side with no plastic sleave or slugs in them ?

[Tombstone (R.I.P.)]

Does L10 have threads inside the sleeve? Maybe the slug fell out. The coils laying on their side are adjusted by gently pushing the windings together or spreading them apart to get a peak power reading. What's your dead key now?

Tombstone

[mugsy]

about 2 watts dk now but i dont think the radio ever had the slug in L10 should i try tuneing L8 and L9

[Tombstone (R.I.P.)]

Try it, you should be able to get some more power out by adjusting those coils.

Tombstone

[mugsy]

yeh i tryed and i cant get any more power

[mugsy]

do you know if i can do this mod ontop of the mosfet 2030
1.replaced R43 (10 Ohm) with 2.7 Ohm resistor
2.replaced R108 (1 Ohm) with .7 Ohm resistor
3.Replaced R76 (2.2k Ohm) with 1k Ohm resistor
4.Re-peak L8 L9 L10 for the maximum power

[Tombstone (R.I.P.)]

I'm not sure about doing that mod with the mosfet. Did you already do that modification?

Tombstone

[Tombstone (R.I.P.)]

I can't get your PC66XL problem out of my mind. If you haven't done the mosfet change over yet that radio should put out decent power and great modulation with a peak up. I suspect that you'll have to check the voltages on the final driver and the final. It's possible that one or both transistors have failed too. You need to look at and check the power transistors for blackening and being burnt up and check for cracks in them and making an open connection. Once you have the radio putting a few watts out again you can probably get variable adjustment on the output power by replacing a power resistor with a variable resistor ( with a little higher than reccommended power rating). As far as L13 goes, if you think you know where it's at but wax is globbed on it covering up the number on the board, just try and chip the wax off gently until you can read the number that's on the board. I don't know anymore to help you, I woild need the radio on my bench, good luick!

Tombstone

[mugsy]

this is exactly what i did www.cbtricks.com/miscellaneous/fet_papers/ekl/graphics/erf2030_cobra_25_mod.pdf

[mugsy]

some one asked have you installed the resistor that is recommended for some radios to control the dead-key threshold? im lost on that one

[Tombstone (R.I.P.)]

I'm not sure about the resistor that you're talking about. Did the modification you got from CB Tricks bring the output power up?

Tombstone