Road King 5640 CB Radio

[SouthernRoller]

Been seeing around here and there, but haven't really heard any reviews on them yet. Anyone been brave enough to purchase one and give it a try? Anyone seen any reviews on them anywhere? What are the pros and cons?

 

[KNY2ADQ]

It is a repackaged Uniden PC.78.

 

[SouthernRoller]

Okay, any input on the Uniden 78?

 

[KNY2ADQ]

basically the same as a Cobra 29, these are good AM only legal CB radios.

 

[SouthernRoller]

Update: Got the Road King 5640 with the peak and tune. Out of the box radio 4watt dead key, peak 18. After the tune 9 watt dead key peak 40. Radio was peaked and tunes using a Sencore CB-42 analyzer, Bird wattmeter, and oscope. Installed radio in the truck connected to a Wilson Trucker 2000 ant, 18 feet of Wilson Coax. SWR 1.3:1 across all 40 channels. Now comes the interesting part, radio was working fine. Until riding into the rising sun for about a hour straight.. Guess the heat reflecting off the windshield was to much. The radio began acting up as in when keyed up the needle on the meter wouldn't even move, tried it on the SWR function and even cranking the calibration all way to the right no needle movement. But the needle would barely move in normal SRF mode when modulating into the mic, but everyone says it sounds like i'm talking way off frequency or something. And the ant warning light flashes when modulating, although SWR is good... So by now you have probably guessed it, i'm not a happy camper and radio is boxed up headed back to the shop it came from....

 

[Dawn]

This is precisely what you get when you get a peak and tweek job and the radio is pushed to the limits. No longer are radios made at this price point with conservative rated parts that loaf along even when pushed. The equipment is meaningless. That sencore is 35 years old and the company hasn't supported in over 20. You really think it's in cal unless someone really good in metrology could get their hands on it and charge 3x what it's worth to do a complete alignment? Would you think it would have been better had it been done on one of my HP8920 service monitors in recent cal in my lab by a real FCC certified and Industry certified communications technician or some golden screwdriver cb expert that may or may not have at minimum a GROL license taken from a question pool, following cheat books, and couldn't do component level repair to save their @ss?
I'm smart enough with over 40 years of being a bench tech to have told you that you would have been wasting your money for a peak and tune job and reject the job. I have integrity, licenses, and reputation to preserve. Sure, you see the power and the swing, you're limiter's disabled, you might have some extra wires hotwiring the pll for more channels.You pay for it in the end. Dearly.
Now, who is going to pay for the repair? Is this guy going to stand by his job an warranty the radio? You think Road King is going to? Sorry to sound so caustic and jaded, but should anyone bother to read what's been written here or bothered to search, peek and tweeks ultimately lead to failure especially on newer radios. Sorry this happened. Once bitten, you should be twice shy.

 

[JayMojave]

Hello Dump Trucker: Sorry to hear the radio started to have problems and such.

Modifying the radio from the stock power levels to higher power levels may have caused the SRF indication of low or no RF Output. How did you measure the SWR with little or no RF Output?
I would think driving into the rising Sun shouldn't have caused that much heat to make the radio brake.
I can see a Dump Truck vibrating may cause problems.

How ever trouble shooting the radio and seeing what really happened will tell the real story. The modification is considered a possible problem as this seems to be the only thing touched in the radio. The bad thing is the amount of RF Output gain as compared to actual gain of increasing your range, is really NOT worth pushing the radios transmitter to the limits, causing reliability problems. The manufactures have little dudes running around wearing bow ties (bean counters) wanting to cut costs to increase the profit margin. They didn't do us any favors by designing and manufacturing the radios with expensive transmitter parts that can be easily modified to a "significant amount of RF Output Power in a reliable way. This condition since the start of the CB Radio manufacturing mass quantities of radios. Yeah some radios did have a extra head room for modifications....

18 watts increased to 40 watts PEP is only 3.5 dB gain, not noticeable. You need at least a 6 dB gain which would be 72 watts PEP, or better a 10dB gain at 180 watts. That's what small 150 to 250 watt amps are so popular. So running a stock radio with good audio into a small amp is way better.

Many years ago I bought a old 1974 Dodge Duster from a friend as a transportation car. Needed a tune up, battery, oil change, filters, and major cleaning but for 50 dollars American I couldn't complain, it even came with a little cheapie CB radio and M-125 antenna, great!

I owned the car for years and the little CB radio worked like a charm taking to the locals going thru the mountains and such, and even long distances. I found out later it had a small 50 watt amp installed in the trunk but had black under coating sprayed over it, making it difficult to remove. Thats why the radio worked so well! I sold the car years later to a guy who wanted the engine and trans.

Good Luck

Jay in the Mojave

 

[SouthernRoller]

Jay the SWR measurements were taken when I first installed the radio, everything was working fine then and did for the first couple hours, then like I said after driving into the sunrise for a bit, the radio went kaput!! I have never had a issue with Walcott before, they are the ones that did the peak and tune, no limiters were cut, no coils spread and nothing added. The radio is headed back to them, they are going to warranty it and will issue a full refund if that is what I choose..

 

[ChetsJug]

Two CB shops I hang at both took a peak inside the road king 56 and laughed their butts off. It seems to have been changed once Turner sold the thing. The Chinese are not going to use top quality parts when they can use mediocre and get more profits. One of the fellas, in fact I'll tell who, Marcus at Ladd,s CB next to Loves in Jackson, GA. (I-75, xt201) said it looked like a Cobra noise canceling mic circuitry but with cheesy parts. Most people have heard that the guts were changed. Now this mess of a sales pitch, the mic has a blank back, no name at all. *sigh* Sorry fellas, this is no Road King 56. It's a legal knockoff.

P.S. if anybody is interested, Love's travel centers are running a sale on the Uniden Bearcat 880 AM only CB for $99. I missed last year when they ran the 980 SSB for $99, been kickin my self every since. The 980 will probably be on sale in December, check out the website at loves.com