Uniden 66XL help and tune tips

[CB590]

Pull the cap/resistor mod out, see what the color code is of the resistor, change it to the next higher value, should drop the carrier like you want it to be.

If it is
Brown Black Black (10 Ohms), change to a
Red Red Black (22 Ohms), or
Orange Orange Black (33 Ohms), or
Yellow Purple Black (47 Ohms).

I have even seen up to 100 Ohms (Brown Black Brown) work in some cases.

I am not big on tech work. I get that it's easy but I don't have any resistors here

Just wanted to know if turning down a stock 66XL would be easier to get to a 2-3w DK

This current one is getting good reports and I was entertaining pairing it (if it wasn't modded) with the RM203 in the truck and just pull the Ranger 296DX out and back into the house and just run an AM rig. The 296 is set for the 203 and has been working great but I don't seem to use SSB much when driving for just 20 mins to work or the 2 hour ride down to PA once a month.

I always use AM for traffic and weather and bear reports.

 

[Handy Andy]

If ya' got an old AM/FM "cheapie" - Read : Radio Shack PATROLMAN (@WINKDOGG ) they came with such a filter in their circuits. That may just be the proper size in both lead-dress and pinout to work for your Radio.

​

Although originally for AM - they also used the variable cap inside to tune thru the band of Police and Fire (WX in some areas) although they performed poorly, they used a wider Ceramic IF Filter to obtain the bandwidth for the AM signal decoding - you heard more "fuzz" on the audio - but you to "detune" the frequency to obtain one of the deviating sidebands of the FM signal to hear some of their chit chat if they were close enough to you...Police FM wasn't perfect and they did produce some AM envelope due to the nature of the transmission.

IF they were on top of you - you'd know it - these things were not very selective so they were prone to image and bleed - and teen-kids driving around using dads car...well, used them for that reason - they used to listen for this noise to avoid the cops.

Later on they even expanded the Flavoradio line to include FM...

Images (c) Radio Shack - Tandy
​

These were still quite popular with the sports fans going to Arenas they needed something to help filter out all that noise and the echos. They usually tuned into the local Radio broadcast so they could hear some of the announcer doing the gameplay. Nothing like seeing your family "wired up" with those annoying little supplied earphone looking like some throwback to the MIB/CIA/FBI days...

So as you dig thru garage sales, see if any of these little ditty's pop up. They may not work - but can provide the parts you need...

:+> Andy <+:

 

[CB590]

I don't get it. First they clipped D9 and did the normal clip n tune. Then they did the swing mod as well. The radio is getting good reports here at the qth. I'm torn between keeping it or just selling it. It's doing like 3w dk and swinging from what I can tell to 5-6w on my non peak meter. Seller said his Dosey was showing almost 20w. I'm guessing 15-17w.

 

[Handy Andy]

Man this is heartbreaking...

Looked good in the photo - board has been pretty much kept preserved. So it's been stored in good condition just not sure of operational condition.

So if they've done these "mods" - I wouldn't give up on the radio. Why? It works and shows good physical condition.

IT would appear that they wanted a backup spare...

And in light of the mods, they are not that hard to repair. It just gets messy. Undoing it would not be that hard.

Clipping D9 is the "usual" CLIP of the Clip n' TUNE - don't feel like it's diminished the value of the radio - these boards used a limiter design that was pretty stiff in the first place. There was more than one way in "clip" to skin a cap - er, cat...

​

In light of the advice, ripping out the parts versus just a simple unsolder a lead and review the results - well the "Key of C" refers to keep it centered, you really only need to change some values - C70 is a 1uF Electrolytic, you LOWER IT'S VALUE to reduce the signal the Limiter detects and works with. This "Key of C" cap change also changes the "tone" of where the limiter "centers" in vocal range and is most effective - higher tones you don't really need and are the most prone to IMD (Intermod and Bleed) so they pushed the 1uF idea to make the limiter work more like a compressor - it took in everything.

So Put in D9 and lessen the C70 impact by lowering the value.

To sharpen the limiter recovery time - reduce C91 a 220uF to a SMALLER value. This helps in compression without making the limiter action sound too muddy. Try 10uF or 22uF - 50V. Follow Polarity...

​

They knew enough to keep it stock and not sub much. They just wanted a linear driver to talk on.

I'd keep it...it works and fits...

Hope this helps!

 

[CB590]

This would be the other 66XL my friend has. It's all original. D9 intact as well.

he's willing to swap with me. He doesn't have an amp.

 

[CB590]

At the end of this and thinking about it. I basically have 3 SSB rigs and don't even need this radio. I can easily move the 6666 to the truck, move the 296DX inside to hang with the President Grant.

It was a good thought at the time to get it as they are getting scarcer to get and are great sounding little rigs. The 66XL is up for sale. Rather have some $ back in the fold then a radio collecting dust. I don't even have an antenna switch here at the house, I'm still switching coax manually from one radio to another.

 

[NZ8N]

I have always just paralleled the Base of TR14 (or C91) to Ground with a 1k to 2.2k resistor, leaving everything else intact. This "bleeds" off the voltage stored in C91, which is your main Sample and Hold capacitor in the circuit, then readjust VR5 to tighten up the AMC again. This causes C91 to release a LOT faster, and makes it more of a Syllabic Speech Compressor rather than a "hold too long" AMC Circuit.
In the Cobra 29 series, TR18 or C71.

Remember, the AMC Circuit ONLY reacts to the negative voltage swings, not the positive. Else, these "Forward Swing Mods" would not work. Look at the direction of D9, the Cathode is towards the Reactance Diode, D10, not away from. This sets up the AMC to only react to the negative swings. And the capacitors in the AMC Circuit are reverse polarity reference to Ground (or Negative voltages).

 

[CB590]

Going to give it to my son. He has his HAM tech ticket too. But a CB that's free is good for an 18 yo that just got his car.

 

[Robalo]

Happy New year to all of you wwdx rf ! good luck,good health,good dx and dont cast me a bait ,aim on diet now lol, be happy