Help needed for low band P200

emaucat · Post by **emaucat** » Sun Mar 10, 2002 5:12 pm

LQQKING for someone with
information on mods for
a low band P200 range
change. Anyone out there
ever made a p200 work on
52.525O Mhz

Dan

Guest · Post by **Guest** » Sun Mar 10, 2002 5:15 pm

They will got to 52.525 just fine, anything much above that and it takes some major modes to the inside of the radio. I don't know of anyone who has done it in my 34 years in the business. Good luck to you.

MC

Monty · Post by **Monty** » Sun Mar 10, 2002 6:06 pm

Hi Dan:

Sorry to see you being miss-led by a
a troll memeber.

[ Monty Crisco is Troll User who is using
other names here on the group.]

Stock the P200's in general will not
go to to far into the Ham Range without
some modifications

Here is a photo of the 2 laser trim caps
that need to be addressed. They are the ones
on the left.

<img src="http://www2.4dcomm.com/metrotech/lb_pic2.jpg">

If you need details, we have some good
information on the " How To"

Monty

<font size=-1>[ This Message was edited by: [email protected] on 2002-03-10 21:08 ]</font>

Ray D. O'Mann #2 · Post by **Ray D. O'Mann #2** » Mon Mar 11, 2002 8:25 pm

HEY MONTY! That looks interesting, does this apply to the 42-50 MHz MT1000? I have hacked the codeplug to above 52 Megs, but the VCO (I assumed) craps out. Works ok at 52 though. I'll check the mods pages again.

Monty · Post by **Monty** » Mon Mar 11, 2002 8:54 pm

Hi:

I have a fellow associate who is a engineer
with abilities far beyond me ! he has been
addressing the laser Trim Cap issue, figured
out all the tank circuit Rnages and made a
quick change in the value.

The Trim Caps appear to be around 9.1pf, he
tried 6-7 pf, and although the range increased a samll amount, it was not enough
to go all the way to 54Mhz.

Due to time, he had to suspend the project, and we have been thinking about removing 1 or
2 turns off the Coil...

We have still been hunting for someone who has made the proper mods to go to 54Mhz

Its on the oposite side....

<img src="http://www2.4dcomm.com/metrotech/lb_pic3.jpg">

<font size=-1>[ This Message was edited by: [email protected] on 2002-03-11 23:57 ]</font>

Ray D. O'Mann #2 · Post by **Ray D. O'Mann #2** » Mon Mar 11, 2002 9:09 pm

ok, so ...

#1) If I was to change the caps, to 6pF, I wonder if this would allow operation to, say, 53.07 without unwinding that coil? That is about as far up as I really need to go. Hell, mine wouldn't even work at 52.525.

#2) Where do I get 'em

Monty · Post by **Monty** » Mon Mar 11, 2002 9:24 pm

OK:

Here is what I have found for sure !

Buy the way, the Monty Crsico Account
is a Troll, and has been deleted, so
do not pay attention to that information

I was contacted by a member, and he swears
all that was needed is to change ( Just 1 )
of the Trim Caps....And he could not remember
which one. ( we have not been that sucessfull )

The fellow I am working with is a bit concerned about the Removal / Reinstallation
of the entire VCO block..And Due to my service issues with Motorola, even I do not have the time...

I DO have a few 36-42 Mhz radios with the
Controller and OSC missing, and if you are a
pretty savy tech, perhaps I can send one to
you to experiment on...I am sure it will help
Dan ( emaucat ) as well if you find out for sure.

Changing the Cap I do not think is just the only issue....I truly believe a turn has to be removed to keep the Tank Circuit stable

But one does not really want to Damage a original radio to find out....You Could use
this " Test " radio, try to just modify the
VCO Block, and then use your Controller in the test radio...If that one gets messed up,no loss...

And it saves on the premium 42-50 Mhz radio
from being used as a Experiment....

The laser trim Caps are something even a little new to me, and even I have not had
time to research them....I was hoping someone
else would do it ( Hint Dan ), or you.

So either Dan ( who is a new member ), or you
,let me know what your Tech Skill level is, and if you have the proper test equipment to make the test

Monty