Advice on CB installation or RF knowledge (1 Viewer)

[Beowulf]

I've decided to permanently install a CB in the dash ashtray location (97 FZJ80).   The Uniden 510XL on Christo's tech pages looked great so I picked up one off of eBay for cheap. Christo's instructions say it will mount flush with the dash if you remove the antenna connector on the rear and solder a pigtail. I plan to do this.

So, I made my pilgrimage to the truck stop to buy a length of coax and get some experienced CB advice from the guy with the screaming eagle tatoos.  Tatoo boy tells me *not* to extend the connector and insists doing so will leak RF which is a really bad thing.  Follow-up questions from me were met with the "you're an idiot and I don't have time to explain" attitude (I love that place...)

My questions:
1. Have you installed the Uniden 510 and soldered a pigtail. If so, how does it look and how does it work? (Dash pics?)

2. Is tatoo boy correct about leaking RF?  Will I destroy my son's gonads?

3. Should I use a 90-degree antenna adapter and live with the CB sticking out a little?

4. Can the OEM speaker (8 ohm?) in the lower part of the dash on the DS be used as the external speaker for the CB?

5. Pros and cons for wiring the power to switched vs non-switched +12V.

6. Any other advice or suggestions for a permanent install of the Uniden?  

-B-

 

[cruiserdan]

(Un-rolling my sleeve to get a Winston)

 -B-, I do not know the specifics about the pigtail thingy but I do know that CB is particular about it's coax and antennas. If other than "standard" lengths are used it is difficult to get a good SWR (standing wave ratio) and the radio output will suffer. Also reception will not be as good. In a worst case the radio transmitter will fry.

As far as power goes, I prefer to have a constant power for mine as I want to  be able to have the radio on when the vehicls is stopped, Especially if I am monitoring a channel waiting to hook up with someone . The drawback of couse is you need to remember to turn the dumb thing off :ugh:.

Dan

Oh, I do have an SWR meter, should it attend the meeting with me? :dunno:

 

[Hltoppr]

Although I've only installed a el cheapo radio shack model, my guess is that tatoo (Where's the plane, boss?) boy is probably technically correct, but practically, for your use, overstating the consequences greatly.

CBs are great for car to car transmissions, or line of sight at most, but other than that you might as well get out and yell, "AAA......HELP!!" at the top of your lungs.

Bottom line, I wouldn't worry about the intracacies too much, unless you've got to have the most performance possible out of the unit. Just SWR tune the antenna when you're done and forget about it.

Maybe BMT will chime in here too, as he has his Uniden 510XL mounted permanently in the lower double din spot, and has an aux. speaker where the USDS tweeter used to be. I think he uses a 4" speaker...

...and no, you won't fry your kids gonads with RF from a civilian CB...

(Now a linear proton beam would do some damage....whoops, just a flashback to a prior profession!)

-H-

 

[cruiserdan]

I find that a DU in-line booster works quite well. It's mounted where the crotch cooler was :

 

[moralien]

Remember you went to a truck stop...
They are worried about getting as much power as possible as it is there livelihood. If you’re just worried about staying connected on the trails then I would not sweat it. If it's good enough for Christo then...

 

[Beowulf]

>> Oh, I do have an SWR meter, should it <<
>> attend the meeting with me? <<

Yes please.

-B-

 

[CDN_Cruiser]

B:

No real experience wiring this type of rig, but here are a few thoughts (I've only had my amateur lic about 4 days, so take this for what it's worth!):

By playing with the connector at the back, you are actually playing with the transmission line that runs from the transmitter to the antenna. The RF enegy (the signal) does tend to 'leak' which is why people suggest that you at least use reasonable quality coax for the transmission line. You likely can move the connector as long as you use some good quality line to do so (to limit the amount of loss). I would think that the best stuff to use would be to solder a connection using coax.

As others have noted, you really don't have much to worry about re RF energy for a number of reasons (although it is something to be aware of). You are only running about 4W of power (vs legal KW in amateur radio), you spend most of the time listening vs talking (right?), and (assuming you don't have a lot of leaking RF) you need to be worried about the antenna (ie don't stand at the wrong end of a 1000W output!)

The internal speaker could work, but I would think that it may need some power to amplify.

Good luck!

Cheers, Hugh

 

[Beowulf]

Nick,

While my post was somewhat flippant, my concern is whether leaking RF could affect all the other electronics. There are a lot of ECU's in the side panels, center console, and behind the dash. &nbspecreased performance is a very slight concern. (Except for the kids... and we won't install a linear proton beam. Thanks for the heads up -H- :G )

-B-

 

[cruiserdan]

-B-

As long as the coax is not "wrapped around" any ECU or running parallel to the existing harness, you should be fine.

 

[Beowulf]

Hugh,

>> I would think that the best stuff to use would be to solder a connection using coax.  <<

Tatoo reluctantly gave me a foot of the same coax that he sold me for the antenna cable a few months ago. It appears to be a quality coax.

How would you create the pigtail and solder to the board and the connector and how would you connect the coax shield to the case and the relocated rear panel connector?

-B-

 

[Photoman]

-B-,
Here is a picture of the pigtail if it helps.
Bill

 

[moralien]

Nick,

While my post was somewhat flippant, my concern is whether leaking RF could affect all the other electronics. There are a lot of ECU's in the side panels, center console, and behind the dash.

B,
As long as you don't have the CB "tuned" by a pro to spike the output way up then I would think that you will be fine. Remember to not cut any of the coax running to the antennae and have it properly tuned.

It will help to get a quality antennae as well. I prefer the wilson 1000 hard mount.

Just my .02

 

[DRTDuck]

B-

I followed Slee's instructions for the Uniden 510 as you are going to. I was about a 3/4 job. I went in just fine. You do have to take apart or cut the back of the unit to solder in the extension.

I did not use an external speaker, I have found the speaker within the unit to be just fine. But I don't know why that speaker in the dash couldn't work, just connect the wires and go.

 

[ParadiseCruiser]

Beo -

&nbspetailed response to follow later in the day; sit tight...

Hugh -

Congrats! What's your call ?

R - K6RG

 

[CDN_Cruiser]

Beo -

Hugh - Congrats! What's your call ?

 R - K6RG

Para:

Thanks - Victor Echo Three Hotel Mike Charlie (now in my sig! )

B:

I would wait to see what Para has to say, but you could just replace the screw in connector with one of the common coax radio connectors (eg BNC) that can either be crimped or, ideally, soldered. The transmission line and the line coming from the transmitted would have a male/female connector. For the end soldered to the transmitter, you would solder the shield (braided part) to one connection and the center cable to the other (making sure they don't touch and short) - not easy to do. I'm still learning how to solder and I did an awful job trying to solder a coax connection for a simple antenna ('portable J-pole', not that it matters!).

I can't really see the detail of the picture with the pigtail post, but if people aren't using coax and it works, that's probably all you have to do!

Cheers, Hugh (ps, get your Amateur lic - far better and way cooler and I will have more people to talk to! ) - with both a CB and portable tri-band amateur radio in my truck

 

[fj40crusher]

-B-,
Here is a picture of the pigtail if it helps.
Bill

Now that is a nice and clean install :G

As far as leaking RF goes, just get some good connectors and you will be fine.

 

[TLCgrappler]

You ought to be able to remove the SO 239 connector and simply solder the pigtail coax in through the hole it came from. If it goes to a circuit board, you'll need some sort of strain relieve so you dont pull the board apart accidentally by pullin on the pigtail.

Cant say that Ive seen a female "end of line" coax connector, but I'm sure you might find one. Mouser electronics is a great source of parts for DIY electronics buffs. If not, put a Radio shack plug on the end of your pigtail, buy a "double female" adapter, and you can then put another plug on the end of your antenna feedline. The plugs are usually PL 259, with an adapter for the smaller 52 ohm coax, which is normally rg-58 of some type.

Make certain that the swr your cb transciever is "looking into" on the antenna feedline is within its tolerances. If it is not, you will either toast your final amplifier transistors, or the automatic protections circuitry will throttle back your power to a low level. If you buy a propler antenna and follow the feedline instructions, I think you should be ok.

Try not to run the antenna feedline near and parallel to other wiring.

The speaker will work if your transciever's speaker output matches the 8 ohm impedance. It probably does, but check the specs. Disconnect the speaker from any other source if you are going to use it for the cb.

Agree with the comments from the other hams who have answered. Have been licensed since junior hs (many decades ago) educational hobby and lots of kicks.

Might search for any toyota service bulletins re two way radios. Every once in a while you here ham stories about ECU problems from transmitters. I would also search around for ham radio mobile articles. They will generally be somewhat more knowledgable then the purely CB ones. There are some power line and fusing considerations to be dealt with in these installations that Im not closely familiar with.

 

[BMT]

B...sorry for chiming in so late with my .02c worth. I did install a 510XL under an aftermarket radio in my 94. I used a factory take out speaker I picked up at my local car stereo shop. It is a 4" out of a Toyota but any 4" should work. As far as the ohm rating, it will not fry your speaker output if you use a 4 or 8 ohm. It is the speaker impedence. If you wanted to get technical the 4 ohm will be slightly louder because of the greater resistance that increases the workload on the amplifier. The 8 ohm will run at a lower capacity and not draw as much from the amplifier (not run as efficiently). If you ran two 8 ohm speakers in parallel, it would be the same as running one 4 ohm...but I digress. The lower left dash location is a good spot. I have no problem hearing the conversations. I have mine tapped into the constant lead for the memory on my radio.

 

[si_steve]

Greetings B

I installed the radio shack clone of the uniden 510 and used the standard rear connection connected to a std radio stack antenna. I decided to wire my radio to the battery with a fuse in line -- set for future second battery-- I hope.

The main point -- mine looks just like Slee's; sticks out from dash just a tad. no pig tail necessary.

Extra speaker is a 2" approx. square Radio Shack unit that fits perfectly in that little hole on the left side front of the console.

I am pleased. Steve

 

[ParadiseCruiser]

Beo -

All of your questions have been covered well enough, so my .02c is more like a summary. (This discussion is for HF - high frequency - in particular, 27 mHz were CBs operate. VHF is an entirely different matter). The most important elements, in order, are...
- Radio wave propagation
- Antenna
- Transmission line
- Power.

1. Propagation. Entirely atmospheric, so you have no control.

2. Get the best you can afford. Placement matters, but there are limitations, I know...

3. Tatoo Boy is right: Mess with the T-Line, and all sorts of surprises are possible.

4. Trans-Oceanic contacts are made all the time on 5 watts. Don't be fooled by people who do not understand the importance of 1-3.

>> CBs are great for car to car transmissions, or line of sight at most, but other than that you might as well get out and yell...

A very good many CB installations are done improperly. It's much more capable than most folks realize.

Christo will be the first to tell you that he is not big on radios. He wanted to communicate between cars on the trail, and that was it. Wasn't much interested in anything else.

Personally, I would NOT do the pigtail thing. If you must, follow some of the previous suggestions, but be sure to use shielded transmission line (coax), use the same impedance pigtail as the rest of the line, be sure it is properly grounded on both ends. (How do you place your SWR meter between the radio and the pigtail??)

Any RF leak has the potential to cause trouble. Agreed, at 5 watts it shouldn't be a big thing, but stray RF floating around the radio and dash can cause a few RF bites to the operator now and then, and the potential to interfer with the ECU, however minimal, does exist.

If you would like a bloody long explanation, it would be my pleasure. You know how to find me.

Cheers!

R -

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