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Hmm, it didn't save any of my info!

Midland 79-265
PLL: LC7131 SSB
Problem: Missing LC1

Looking foir someone that may be able to take a picture of the PCB on a Midland 79-265 AM/SSB CB. I am missing LC1 near the back of the PCB, next to the SO239 connector where the antenna plugs in. I got the ...

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Radio Make and Model:
PCB Number:
PLL Number:
Test gear available:
Symptoms:

What is working:

What has been tried:

Did it suddenly happen ?:
Anything else that may be of help?:

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Hey all,

One of my friends brought up an interesting situation for me recently, and I figured I'd come here to see if the techs here might have a solution.

My friend has a new Ranger 2995DX, and he wants a frequency counter wired to it, like an FC-347 or FC-390. Can this be done? I am aware of ...

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Does this amp have an inline blade fuseholder on the positive lead? If so, discard it, and put in a good inline cylindrical fuseholder instead. I've had a couple friends that had the exact same problem you had, both times it was a bad connection in the inline blade fuseholder. If anything else, try ...

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I'm willing to bet that although the NB/ANL switch is being used for the 5khz drop modification, that the NB/ANL is functional on the radio, most likely it's "hard-wired" so the NB/ANL are on all the time.

That's pretty common practice if the person performing the modifications decided to use the ...

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Hi Rick,

C57 was the fault, installed a new capacitor, radio works perfectly. Thank you so much for your time!

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Hi Rick,

I unsoldered one end of R8, no change, fault is still there.

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hi Rick, here are the voltages:

Q3, Base
NB off, 0V
NB on, 2.4V

Q5
NB off, B = 0V, C = 0.6V, E = 0V
NB on, B = 0V, C = 0.6V, E = 0V

Q6
NB off, B = 1.0V, C = 0V, E = 6.8V
NB on, B = 1.0V, C = 0V, E = 6.8V

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Hi Rick, thanks for the quick post!

I checked D1, D2, D3, all good. Adjusting L2 did not help with the scratchy signals on AM, however.

I did clean the NB/ANL button with some contact cleaner to see if the switch was causing the scratchy audio, no change.

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Howdy folks, got a nice Uniden Pro 640e that has an NB/ANL problem.

Make: Uniden
Model: Pro 640e
PCB: PB-105AB
PLL: D2824
Mods done: Galaxy "N" kit installed for extra channels, unlocked clarifier, AMC/ALC turned up a bit

Here's the trouble. When I am receiving a station on AM, and I push in my ...

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Heya folks,

Got another Cobra 2000 GTL in recently that has a frequency counter problem.

This is the PC-497AB main board, frequency counter board PC-370AB 1/3.

The frequency counter stays at 12.0000 MHZ when the radio is turned on. The clock part seems to function okay.

I replaced the whole ...

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Case closed, ended up selling the radio. Thanks to all who responded!

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Update:

I reinstalled all the original components, no change.

At R47, I get 8V in RX, 0V in TX.
Anode side of D16, 0V in RX, 8V in TX.

Everything is getting switched properly, from the way it looks, might there be a bad capacitor somewhere? Where would I go looking for that?

Thanks for any ...

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Ack! I'm sorry about that.

I saved all the components I pulled, so I went through and checked all the diodes, all check good. The transistor is good also.

As I do not have a signal generator, I can't perform a proper alignment of the RX strip. I can talk to a friend and see if I can borrow his ...

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Thanks for the quick reply, Rick!

I replaced all the diodes in question, as well as TR-14 (2SC1674L). No change, still real low RX. I lifted D68, no change in RX when lifted.

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Howdy folks, I recently got a good shape Cobra 2000 GTL in on a trade, but it has 2 problems.

The board is PC-497AB. This radio has low receive, both in meter and in audio. Stations that normally hit me S-9 barely move the meter. One of my friends suggested that something in the front end of the ...

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Rick,

Thank you for the info, I'll look into it and let you know how I get on. One of my friends is using the radio at this time, I'll get it from him and take care of it soon.

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Yikes....I got lucky on my display...I'll have to see what I can do as far as reducing the current flow to the display. Thanks for the reply!

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Update on the Pace.... I adjust R363, and the meter moves as it should now, but the RX audio went down! I adjust R363 back down, and the RX audio goes back up!

When I switch the meter from the S. RFO setting to SWR or CAL, my receive audio goes up slightly. Turn it back to S. RFO, and it drops ...

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Most excellent, thanks for the replies you two! I'll look into this and let you two know how I get on. Cheers!

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Howdy folks,

I got a bit of an unusual trouble.... I recently acquired an old Pace Sidetalk 1000B 23 channel AM/SSB base from a friend. I cleaned it up, did a tuneup on it, and lined up all the crystals so they are on frequency, for the most part (this radio goes up to 27.605). I didn't really see ...

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I probably have the parts you need to get it going, but I'd check and see if D8 was jumped...sounds like D8 either failed, or it was jumped and it cooked the audio transformer. Let me know.

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I just recently got a new display for my Uniden Pro 640e, board #PB-105AB.

I currently have it hard-wired on the "Dim" setting (it has a Bright/Dim button) to prevent the display from burning out...should I reduce the input voltage to the display further? Or will this setting be fine for the ...

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How do you tell what suffix is on your mosfets? I can't seem to find anything on my IRF520's....can you gimme a hint? I'm gonna be picking up a Galaxy DX88 real soon, and I wanna do this mod... if I can't get it done, I might have GRTS look into it for me. Thanks guys.

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In some cases you do need to do a small re-alignment of the RX, I never did one on my Jackson, and it works fantastic. If you had the time and the tools, it wouldn't hurt to do one, but that is something that is optional.

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Hehe...

I understand your frustration with those displays. I bought this one as a functional radio but DOA display off Fleabay. I reduced the voltage going to the display, and I have a new display coming. The Pro 810e doesn't use a display like the Pro 640e since it's a base, so obviously that isn ...

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Just out of curiousity, were you using this radio as a base or as a mobile? I've done the Schottky diode/2SC2999 transistor swap on a few radios, and while it didn't make a real big difference on a base setup, the results were quite impressive for me in my mobile radio, which is a silver faced ...

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Oh, okay good, let us know what happens with that PLL.

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I'd start with the driver, I have talked to many people that have had problems with the Cobra 200 GTL's and most of them said that the driver was the item that got replaced from Cobra when they sent in the radios for repair. If the driver is good, then you could go to the final section.

Again ...

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Thanks GRTS, this will be taken care of, case closed. Success!

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LOL Redeye, that's about the nuttiest thing I've ever seen....that sorta stuff makes me cringe to think some poor sap bought this item...sad.

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That's super!

Unfortunately, I'm not able to PM anyone, as only admins, moderators, and technical helpers are the only people that can PM, per Scott (The Defpom). If you'd drop me a quick email at Bander_moth@hotmail.com, I can discuss this with you in that manner. Thank you!

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With all these conversions coming out for the IRF520's and ERF2030's, does anyone know of a mosfet mod for the Uniden Pro 810e/640e AM/SSB chassis? The Pro 810e board is #PB-122AB, the Pro 640e board is #PB-105AB. Just curious. Thanks in advance for any info that anyone can provide.

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It's not always the case, my Uniden Pro 810e base station deadkeys 4 watts on AM, and when I modulate, it pretty much just stays there on my Bird 43A wattmeter. It wiggles just a little bit, but the most part it stays right at about 4 watts.

However, when I use my Dosy 4001 test center, I show 4 ...

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If the power meter you are using to check this radio only measures average power, then that's probably why you're seeing backward swing... if you get a meter that reads PEP (forward swing) it might read different, your radio might not have anything wrong with it. Just a suggestion.

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There is a possibility that the VCO is out of alignment, I'd try that first. mark where the current position of the slug is set at, and take a plastic screwdriver and ajust the VCO 1/4 turn either direction, and see if the radio locks on the lower channels. If it does not, it could be a PLL problem ...

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Replace the other ceramic disc capacitor(s) with a ceramic disc capacitor of .01 uf and a voltage of 1-2kv. These are pretty common, you can get them reasonable. Make sure the new one has an operating voltage of 1kv or better (2kv is best) or otherwise, you'll pop the new one.

Regards,
Rick ...

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Okay,

I'd recommend you try the things I suggested in my first post, sounds like it 'could' be a stuck relay, or it's not seated very well in the socket, or the CB/PA switch is dirty. Check those first if you haven't done so already, let us know what happens. If those don't work, we can move to ...

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Oops, sorry about not being logged in on Yahoo, I'll leave it up later on today if you wish to contact me. I'll work something out with you. Cheers!

Regards,
Rick (Triple 7)

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I have an extra RCI-8719 PLL chip that was a good pull from a Cobra 148GTL radio, if you need it, send me a PM. I'll get it to you.

Regards,
Rick (Triple 7)

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First of all, some specifics about the radio does or does not do will help.

Does the relay activate when you key the mic?

Check the relay and make sure it is seated firmly in the socket it goes in.

Check all the crystals to make sure they are all firmly inserted in their respective sockets.

If ...

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Most excellent, thanks for taking the time to look! I'll keep this updated as needed. Cheers!

Regards,
Rick (Triple 7)

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Sure thing, GRTS... I'll get a pic up... it's a slightly fuzzy, though.

The display from a Uniden Pro 540e (the AM only version of the 640e) has the same display in it also. So a 640e or 540e display will work. Here's a couple pics.

http://img.photobucket.com/albums/v46/chaos_AD/Picture057.jpg ...

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I believe someone may have previously posted that was looking for one of these, but can't be sure...

I have a Uniden Pro 640e AM/SSB mobile radio that works great, but the some of the segments on the channel readout are burned out, and the channel/meter readout is all one sealed unit. Uniden quit ...

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Here's a link to an IRF520 dual final conversion kit for sale.

http://cgi.ebay.com/Dual-Final-Upgrade-for-Galaxy-959-949-TR696_W0QQitemZ260241019096QQihZ016QQcategoryZ40055QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Yes, I know it's off fleabay, but that's the only place I could find a kit. I did try ...

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Hmm, sounds like the amp board (with the 8 mosfets) isn't keying up when you TX on the radio.... maybe a relay is bad (not switching or stuck) or the switching circuit isn't functioning. Just my take on it.

Perhaps a tech could help you out in this matter, but that's what it sounds like to me ...

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RM Italy amps are junk, very poorly made, same with those new "Palomar" amps they have running around Ebay these days, also garbage. Neither of these amps don't really have the proper biasing to the transistors, so they tend to sound bad on SSB.

If you want a good box, get yourself a Texas Star ...

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2.5 watts is plenty good for a Skipper 300, I usually run at 2 watts, as the more imput you have on the tubes, the quicker the tubes burn out, because higher deadkey = more current on the plates of the tubes. AM/FM is hard on tubes, because you're applying constant current to the tubes at all times ...

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Feedback/RFI and excessive deadkey into the box are a couple things that come to mind if you're swinging backwards... Check your deadkey, make sure you're not putting some nasty high deadkey into the box, 3-4 watts deadkey is all you need for a deadkey input, and let it swing.

Check and make sure ...

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I did swap out that 10.2417 Xtal for a 10.240, and changed the varicap, works real good, although there is a slight drift on SSB, nothing real bad, however.

I did notice that pin 20 is the 5/10kc offset pin, do I need to tie that high to get the 10kc offset? It's tied low currently. If I need to ...

The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Search found 74 matches

Re: Needing a picture of the PCB of a Midland 79-265

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