Homeade preamp "ear kit"

[COONHUNTIN' COBRA FAN]

Does anyone have any good ideas for a homeade internal earkit that actually works like it should?

If so could you tell me how to make and install one in a 139XLR?


Thanks in advance!!

[Rick]

I do not think putting a pre-amp in the radio will cure the problem; it is like taking a sledgehammer to crack a nut. This will not fix the underlying problem.

[COONHUNTIN' COBRA FAN]

Yeah I know it's not the best thing to do.... but not having a Tech close by I don't have alot of options.... I tried the preamp on a small linear and it made great improvements over the current RX... I thought if I could install an onboard preamp it would take away the need for running the linear preamp!

73's to ya Rick!

I'm still open to suggestions if you think of any alternatives to a Tech tuning it! What equipment would I need to do an alignment on the RX side anyway? Is it anything I could buy or build relatively cheap???

Thanks again!

[Rick]

To do the RX alignment you need a RF signal generator, they are not cheap.

To try to do the alignment without RF signal generator is not a good idea.
However, if you must try this.
You will need a second radio on the same channel in the TX mode with very little output power connect to a dummy load, so it just shows on the signal meter of the 139XLR, then with plastic alignment tool (this is like a screwdriver) do not use a metal screwdriver as this will only damage the coils cores you are about adjust.

Start by adjusting L3, L4, L5, L6, L7, and L8 for max reading on the signal meter.
You should not need to adjust the coil cores more than about ½ to 1 turn unless someone has really upset the tuning.

They is a diagram of my pre-amp on CBTricks, check out the link.
http://www.cbtricks.com/members/rick_eu ... re_amp.pdf

[COONHUNTIN' COBRA FAN]

RICK IS THE MAN!!!!


So many thanks again Rick!! You are truly a good man! I have read through alot of this forum hoping to learn something that might be useful and the one thing I see repetively......

You being a generous person and taking the time out of your day to read and research other peoples problems and offer your assistance..

I am sure that you don't here the words THANK YOU near as often as you should!!!

Keep the good Karma rolling and 73's all the way around!!

I will be doing what I can with the 139XLR recieve and I'll get back to you in a day or so to let you know the results!!

Thanks again!!
Shane Pedigo
a.k.a. "DRIFTER"