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Boxcar
| | Posted on Sunday, May 11, 2003 - 3:49 pm: | 
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Just wanted to throw a few questions out there to you old timers on a radio I just got recently. I recently bought an old president madison radio and it works terrific but I do have a few questions here. The receive part is very sensitive. When I hear people out in the distance the needle barely moves but when someone with a strong and loud radio keys up, it almost slams the needle to the right. I've had a buddy hit me at a strong "9" on several different radio's that I have but this madison's meter is all the way to the right pretty much. I also am curious on this 858 chip which is not really broad banded too much. There's a six position switch where the headphone jack is on the front and switch "1" should have the regular 11 meter but the frequencies jump around starting around channel 28 or so. Can't get channel 30 at all(27.305). Anyways, don't get me wrong, I love this radio because I'm a huge fan of these madisons but have you guys ran into any problems with the receive too sensitive? Maybe I just need to adjust something but any specs would be appreciated. I have been searching for all the specs on this radio like variable numbers inside the radio, power mods, audio limiters etc. but I would really like to take out the channels since I'm pretty much just a 11 meter junkee. Oh, and by the way, hope I didn't mean to offend anybody on the old timers comment!! Ha!!! You ain't old unless you feel it right? Then I'm getting old!! Ha!! Anyways.................
BoXCaR |
2600
| | Posted on Tuesday, May 13, 2003 - 2:45 am: |
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Getting the thing aligned is probably the place to start. If the receiver really is broken, one or more of the tuning slugs may provide a clue as to where the problem lies. A slug that SHOULD have a sharp peak (and doesn't) can indicate that the trouble is in that circuit. Could just be a bad case of a receiver that got "tuned with a wattmeter".
Some folks will look up which slugs to peak for max transmit power, and decide "Hey there's a bunch more in here. Wonder if this one makes the meter go any higher?" If they simply put the slug back where it was before twisting it, no harm is done. Usually, Joe Screwdriver has his tunnel-vision focused on the watt scale, looking for one more tick-mark on the needle, turning each slug one by one. Who knows where they were set before? By the time this guy is done, the receiver is down six S-units from what it should be hearing.
Around here we call that one "Truck-Stop Super Receive".
73 |
Boxcar
| | Posted on Tuesday, May 13, 2003 - 4:31 pm: |
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Thanks for the info 2600!! I did find that the receive just needed turned down a little, that's all. I still am trying to figure out which finals are the transmit power because every final in this radio is marked "C1419". I usually see "1969" finals in every radio i've messed with so I am thinking this hasn't been changed out for more watts because all I get is 3 swinging 18 watts. Have you ever modified one of these madison radio's before??? |
CM 3885
| | Posted on Wednesday, May 14, 2003 - 2:04 pm: |
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Hey 2600. You ever have any guys down there that work out of their vehicles claiming to be a CB tech??? |
2600
| | Posted on Thursday, May 15, 2003 - 1:07 am: |
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Hiya CM3885,
I've been located in this building for 23 years. "Roadside" techs have come and gone regularly since we first opened in 1975, usually before I hear about them. Can't really chime in when folks want to gripe about these guys. The first heads-up I usually get when they hang out their shingle is a flurry of sabotaged radios and flustered owners. I usually wish the "roadside" guys good health and long life. Griping about them would be like biting the hand that feeds, so to speak.
Hey Boxcar,
The "1419" transistor in that radio is the regulator for the AM carrier power. Getting full swing with a low carrier on this chassis is pretty involved. It can be done, but only by changing the original "regulator" circuit completely. The large aluminum plate that the '1419' transistor is mounted on has two similar-looking parts at the opposite end, near the front panel of the radio. Typically, a small flat bias diode will be mounted in front of them, hiding the type numbers. The one nearest the front is the driver, originally a 2SC1306. The factory final, to its right was 2SC1307. They have been out of production for a long time, despite counterfeits that have their original number scraped off and "1307" rubber-stamped onto the front. The modern-day 2SC2166 driver and 2SC1969 final will work in this radio, but getting the bias set on a 2SC1969 final may require changing a resistor.
Your Madison was made by Uniden, back when they had a factory in Japan. The same circuit board appeared in models sold by Radio Shack, TRC-457/458, Robyn's SB-520D, Cobra's 139XLR/138XLR, and the original (4-pin mike) President Washington. The same "swing" setup works on them all. I don't have a firm plan to put up a step-by-step with pictures for the "full-swing" variable key for that radio. The current web project is "Adding lower receive to the Browning Mark III" (both versions). The old 858 SSB radios are on the "someday" list. The circuit I use for that looks a little like scribbled shorthand in the margin of our copy of the schematic. Wouldn't do much good to pass it along in that form.
I hesitate even to admit we have that one. For years I have told people that when some guy says he's the only one with some "secret" setup, to make a radio deliver more (power, audio, etc.) they should hold onto their wallet tightly, and walk the other way. Such claims are nearly always fraudulent. It's not magic, just engineering. I really wish someone else would work it out and publish it. Would get me off the hook, anyway.
73 |
CM 3885
| | Posted on Thursday, May 15, 2003 - 1:50 pm: |
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Can i chime in here? LOL
Were I live the old Robyn SB 52D is very popular(dont ask me why i dont like them that well) for some reason guys claim they have more audio punch than any other CB radio! The ones i always hear sure seem to sound good but not as loud as say a galaxy or the like. I know a guy that claims his will do 50 watts pep on SSB and key 20 watts and swing to 50 on AM! LOL |
Electronic101
| | Posted on Thursday, May 15, 2003 - 9:07 pm: |
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If you are looking for a Service Manual & Schematics for your Madison, try to find a Sams Photofact CB Radio Series manual # 179. Ebay might have one for a cheap price. |
Mech
| | Posted on Saturday, May 17, 2003 - 8:01 pm: |
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Boxcar, If you ever need parts for a Madison give me a holler! I have one in my storage closet that took a serious spill years back! But it still works. If you ever need parts for yours let me know. Mike DX 8193 |
Boxcar
| | Posted on Sunday, May 18, 2003 - 12:49 am: |
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Hey Guys, thanks for all the posts on this radio. I'm not sure if I want to mess with the finals and increase the power as of yet. Might do a little research first. This is an oldie and still works great. Not sure if I want to tinker too much on the inside because radio's go for a lot more on auction sites when they're not messed with too much on the inside. Might just leave it where it's at and if I throw a astatic D104 desktop mic on it, it will sound awesome anyway. Thanks again guys!!!
BoXCaR |
Sofkow
| | Posted on Sunday, May 18, 2003 - 1:54 pm: |
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I have a Madison and I am in love with it. I didn't want to mess with the inside much, so we just peaked it a bit and wired in a Dosy autoscan. It's very simple to return it to stock. I have a Tug8 hooked up to it and it is very very loud... |
Xlaxx
| | Posted on Thursday, May 22, 2003 - 8:20 am: |
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Where is R 124 on this radio? Found R126, R131, TR 24,... No schematic or Sam's Photofacts.
Thanks
XLAXX |
Adshar64
| | Posted on Friday, May 23, 2003 - 5:48 am: |
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R124 sits about 1/4 " direct left of R126 and by the right side of R123 |
Xlaxx
| | Posted on Friday, May 23, 2003 - 8:55 am: |
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Thanks guys! Found it!
Did the mods on this radio,... awesome reports.
XLAXX |
Boxcar
| | Posted on Sunday, May 25, 2003 - 3:26 pm: |
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What kind of mods did you do Xlaxx?? Modulation?? Power?? |
CM 3885
| | Posted on Sunday, May 25, 2003 - 5:50 pm: |
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Did you do the 12 volt to final mods and the NPC RC mods?? I used to own a late model madiosn with the analogue clock and i did the mods to it and it was short of awesome on the air.. Now some models of the madison had the variable pot for the power supplier and some didnt.. The one i had was the early uniden version 8719 PLL chip with the old clock and it had the variable pot. I later got a newer version uniden (1989) version with the digital clock and it didnt have the varable pot and it didnt take the mods as well as i wanted it to... But IMHO the madison is an awesome radio with superb receive. I actually prefer the 8719 PLL uniden madison ovedr the Cobra 2000GTL!! |
Xlaxx
| | Posted on Monday, May 26, 2003 - 10:37 am: |
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Boxcar/CM3885-
Yes, I just bought a Madison. It's a Uniden, 8719pll, with ANALOG clock. When I bought this radio, it was dk'ing about 4-5W swing 13W. I read Adshar64's NPC/RC mod about the Grant and the 12 volt to finals. I also saw the mods for TR 24, R126, R124, R131.
With the help from Haymaker 150 VA, Lon/Tech 808, and 307,...performed these mods and it does exactly what Adshar64 says,... 2W dk swing 25W. Excellent reports with a D104 handheld. I did clip R131 but probably didn't need to since TR 24 was gone already when I opened up the rig. My pll was hacked a little but the Madison is on freq. AM, LSB, USB. I have not put extra channels in yet. Haymaker was saying,..."I know I can get more outta this radio" LOL
I bought this radio because I love my 148GTL and Grant XL (Same boards and tweaks). But I really like the clock (IT WORKS!) and I like the BIG RADIO look. Everything works on it. CM3885,... I agree too, the Madison is just like the Cobra 2000 GTL except it doesn't have the heavy wood casing and vented, inner metal cover. It's kinda funny because when I bought it, the guys were commenting on how nice it looked and how similar it was to the 2000 GTL.
Anyway, looking forward to its service.
Boxcar, do the mods,... they work.
XLAXX |
Boxcar
| | Posted on Monday, May 26, 2003 - 4:44 pm: |
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Hey Xlaxx, I might have to ask detail by detail on this madison because I've never done any mods on this kind of radio before. I do have some specs on it but not much so I haven't touched it yet. I got it off of yahoo auctions about a month back but I know the finals are still the stock ones. It gets about 3 watts and swings to about 17 and that's it. What all audio resistors/limiters does this radio have and which one would be the best to cut without messing up sideband? I have my eye out on some photofacts but until they get here I guess I'm kind of in the dark on what to do. I do a lot of radio work myself but that's depending on how good the info is that i get from others. Any help would be highly appreciated there!!! Oh, my madison is the older president model.
Thanks!!
BoXCaR |
CM 3885
| | Posted on Monday, May 26, 2003 - 7:03 pm: |
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I dunno why but ive always liked the looks of the madison compared to the 2000. Ilike the features of the 2000 but for some reasn the chrome front and the wood case just dont do it for me in the looks category.. |
Xlaxx
| | Posted on Monday, May 26, 2003 - 9:48 pm: |
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Boxcar-
The Sams Photofacts you need is #179, as in previous posts on this thread.
Mine is a Uniden,... there is a difference. My finals were 1969 (for sure) and 2133 (I can't remember now and the cover is back on it,...sorry,...I can find out though). Anyway, your mods may be a little different as 2600 mentions and could be involved. I opened the radio up and that's what was in it so it might have had different finals in it when it was new/stock.
Click on Adshar64's profile and email him,... I did and he was VERY helpful. Also, don't hesitate to ask or email Tech 808 OR Tech 307. I know I bothered them a bit about it but their experience and recommendations are worth it.
Adshar64 provided the details under Grant mods 12 volt to finals on the Open Forum. It's pretty much word for word there.
Let me know if I can help you out.
XLAXX |
Xlaxx
| | Posted on Thursday, May 29, 2003 - 8:14 am: |
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Anyone out there have an external speaker for the Uniden President Madison they might want to part with and sell?
Have been searching and emailing for one but no replies or responses.
Thanks
XLAXX |
sofkow
| | Posted on Thursday, May 29, 2003 - 11:41 am: |
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I can't imagine may people willing to part with them unless they are selling the radio as well...I procured 2 from ebay recently. In fact...I just checked E-bay and there are 3 up for grabs right now. |
Xlaxx
| | Posted on Thursday, May 29, 2003 - 10:23 pm: |
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Sofkow-
What's your email address?
Also, when you are in LSB or USB on the Madison,... does your MOD/SWR meter function??
Thanks
XLAXX |
Kc0gxz
| | Posted on Thursday, June 05, 2003 - 6:29 pm: |
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Hey Boxcar....
Do not do the NPC mod that Xlaxx is talking about. He has the newer version Madison than yours. Completely different chassis. You have the 200 channel version.
I still have a Cobra 139XLR in storage here with the same 858 chassis as yours. We can get your receive straightened out and the frequencies wired the way they should be. If done right, that radio should have over 200 frequencies in it with very little power loss on each end of the band.
I think you still have my phone number. If not, you can get it from Gary.
Jeff, kc0gxz. |
Boxcar
| | Posted on Thursday, June 05, 2003 - 7:48 pm: |
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Hey Jeff,
I'll give you a shout sometime this weekend. I really just want to push up the power a little. Maybe if you want, you can stop by and I'll show you the radio and what i'm talking about. The extra channels really don't concern me all that much since it already has the extra's in it but just the power mod. Trying to get this radio room a little more organized because I built a shelf for all my radio's and moved everything downstairs.
BoXCaR |
Xlaxx
| | Posted on Thursday, June 05, 2003 - 10:13 pm: |
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Boxcar-
I agree with kc0gxz, sounds like yours IS a different chassis. Also, your 858 pll is much more expandable than the 8719. I did not put channels in mine either. Only the MOD and PWR mods. Sofkow is right though, it's pretty easy to get it back to stock.
XLAXX |
Adshar64
| | Posted on Friday, June 06, 2003 - 1:34 am: |
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With xtal switching and pll/vco mods the 8719 chassis can cover 4mhz with no vco dropout.Also the mb8719 will slide like no other with custom xtals fitted.You will not believe range available ie up to 800kc
see
http://homepages.ihug.com.au/~adshar/2000.html
See my latest posts under washington -cobra 2000.
858 chassis has a inherent problem with rf feedback and anal xtals . However I do have one and its one "Washington"of my favorites as a classic. I have some extensive 858 posts on here. Use search to find.See my 858 channel map incl 5kc mod here. I spent a long time making this and is all my own work.
http://homepages.ihug.com.au/~adshar/858chart.xls
cheers
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Kc0gxz
| | Posted on Friday, June 06, 2003 - 11:58 pm: |
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Adshar64....
You're right. The 858 (200+ frequency capability)was THEE ultimate PLL chip until the FCC out-lawed it. And I never could figure that out either. Why did the FCC out-law that chip and then OK the 8719 chip that followed? For awhile, the non-modable 8734 was used but soon after that, the 8719 showed up in the new CBs. What's the story there?
Maybe someone else on the forum knows the "how and why" story.
Anyone?
Jeff, kc0gxz |
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