CB radio connectors and setup

[toomanytoys]

Well.. after a while of having most of the bits in the shed, I am finally trying to install..
Anyone got a collection of connectors and a meter of coax and can help me set it up fri eve at shipston??

If I see a truckstop on the way I will see what I can pick up..

[Aidan]

I can send the swr meter down with the oirish, might have some coax but no connectors, the oirish probably can bring a spare aerial

[v-lux]

I carry a SWR meter in my truck all the time, so that'll be there.

[toomanytoys]

I've got a "twigg", CB and mic.. I even have a swr meter, but dont know (if it works) and how to use it to check it..

Another event wont hurt if its not up and running.. I've managed this long.. I just thought I could actually tick this one off.. finally..

[max and caddy]

10-4 for a rodger? might dig my old set out if theres syncro folk on it!

[ghost123uk]

I've got a "twigg", CB and mic.. I even have a swr meter, but dont know (if it works) and how to use it to check it..

Another event wont hurt if its not up and running.. I've managed this long.. I just thought I could actually tick this one off.. finally..

Simon, you going to Bustypes ?

If you are look me up, for 15 years + I owned and ran the local electronics shop and CB sales / repair / install was a fair chunk of what I did

[toomanytoys]

Didnt get installed.. no connectors and coax..
Very unlikely I shall be at bustypes or any other show, Syncropendance and perhaps another Syncro event later.. thats it for this year now..

I'll have to pick up the bits when I can.. or get my Dad/bro to stop in a truckstop (I'm not in the country much and time is limited), as they are both truckers..
Just need a 90 degree coax to ariel connector (need to see what one it needs), 1m of coax and connector for CB.. nowhere local has owt..

[ghost123uk]

If you like I can stick what you need in a jiffy bag and post it to you.

Just need to know which right angle connector you need, there are 2 types but the most common one is called a "DV" connector and is the type that fits onto a "dome" (shaped) aerial mounting like this setup =



Those type plugs require careful soldering. I can solder it on if you wish.

The other, less common one is like this setup =



I also have a printout on how to use the SWR meter to tune the length of the aerial (what aerial have you got ?)
Do you have the short "patch cable" for the SWR meter, if not I can include one of those too.

The plug for the CB end is a standard item, so no complication there.
Let me know.

p.s. Price = a beer or 2 if we ever meet up

[ghost123uk]

Here is my "how to" on adjusting the "SWR" (Standing Wave Ratio) on a CB radio areial, uploaded so anyone can use / print it

Right, so we cannot upload MS Word (DOC) files, nor PDF files

Here it is in plain text then, you can cut and paste it into MS word or whatever yourselves

CB aerial SWR adjustment Instructions


You will need an SWR meter, a patch lead, and tools to adjust the length of the aerial.
( see note * below re “Dial a Match” type aerials )

IMPORTANMT NOTE = Don’t touch the aerial when the microphone key is pressed, you can get a bit of an unpleasant electric shock from it !!

1, Connect an SWR meter between the CB and the aerial lead, using a patch lead, make sure the SWR meter is connected the right way round, the 2 sockets will be labelled “ANT” (i.e. the Aerial !) and “TX” (i.e. the CB set, TX is short for “Transmitter”) - It should be easy to figure out which is which !!

2, Switch the CB on and set on channel 20, use the low power setting switch if you have one.

3, Set the switch on the SWR meter to the position marked “FWD” or “CAL” and turn the adjusting knob ½ way up.

4, Briefly press the microphones transmit button / key, and note how far the needle on the SWR meter moves, now adjust the knob until the needle just moves neatly to the right hand side of the scale when the transmit button is pressed.( to the position usually marked “CAL” or “SET” ) Don't press the mike for more than 2 or 3 seconds at a time. If you can't get the needle to go far enough over, switch the CB to high power.

5, Now set the switch on the SWR meter to the position marked "REF”, (or sometimes "SWR") don't alter the setting of the knob.

6, Briefly press the mike key again and quickly note how far the needle moves, if it goes more than 1/2 way be careful as pressing the mike key for more than a second or two could damage the CB set.

7, The idea is to adjust the aerial up or down in length until the needle on the SWR meter moves as little as possible. ( see note * below re “Dial a Match” type aerials )

8, Most aerials will have some means of adjusting the length that is fairly obvious, the amount of adjustment is largely dependant on the size of the aerial, a small car aerial should be moved about 1/4 of an inch at a time, a large base station aerial may be moved 6 or more inches at a time until fine adjustment. On some car aerials the shortest position may still not be short enough to get the reading down and so you might need to cut some off the tip. Obviously care is needed here as it is difficult to add it back if you cut too much off! Cutting just a ¼” at a time is recommended, whilst each time checking the effect on the reading of the SWR meter.

9, When this has been done the SWR reading should be less than 1.5 ideally, but a bit over this will not do any harm and will hardly affect the signal.

10, Finally check the readings on channel 1 and channel 40 using the same procedure, but without adjusting the aerial, Note = The readings on channel 1 and 40 may be slightly higher than the reading in the middle, (i.e. channel 20), this is normal on car CB aerials.

P.S. while the efficiency of the aerial is at its best when the SWR reading is lowest, anything below 2 is considered ok, above 2 will start to make a difference, above 3 is bad for the CB set.
If you need further assistance call an expert ( Me !! )

* Note re “Dial a Match” type aerials = On these you don’t alter the length, you screw the little chrome rings up and down the threads to get the minimum reading on the meter (when set to “REF”), as in step 7 above. The rings must be moved together and gently locked together when the correct position is found. A small movement up and down can make a big difference to the setting on these so fine adjustment may be required.

[toomanytoys]

Your a top bloke...
first one is the one I need.. I have what looks like an identicle mount to that..

SWR.. cool.. maybe we should put that in the wiki??

Beers at the ready..

[ghost123uk]

first one is the one I need.. I have what looks like an identicle mount to that..

OK, sure you only need 1Mtr of coax ?

Would you like me to put the plugs on both ends ? ( or do you have to thread the coax through a hole ?)

Do you need a patch lead for the SWR meter ?

Send me a pm with your address and then consider it done

SWR.. cool.. maybe we should put that in the wiki??

Aye, I don't think I have sufficient privileges to add categories (26.6 ?) - if you have, feel free

[toomanytoys]

PM on its way..

Er, dont think I can add to wiki either..

[ghost123uk]

Si, your bits will be posted today.

Whilst I was soldering it together it got me thinking.

Who out of those reading this have :-

a) - The older 40 channel "UK" band CB's, marked with "27/81" in a little circle somewhere on the set.
b) - The later 40 channel "EU" sets marked "CEPT" or "PR27"
c) - The latest type 80 channel sets covering both of the above bands.

To be honest I have not used the newer CEPT bands much and do not know how much activity is on them. The old "UK" band is still, I believe, more popular.

Please note, if you have a Cobra, Stalker, President, etc with a.m. and SSB, then best keep that to yourself ! (Though I note that legal SSB and a.m. radios are now available )

[toomanytoys]

My York is 27/81.. and I first used it when I was 14... its still in its original box.....

Hope it hasnt suffered in storage..

I have another set that was given to me (IIRC 80 channel), but Mocki siad I should use it as a door stop, so its prob a pile of junk...

[v-lux]

Here's a question for you that's been bugging me for ages.

When I first installed my cb it was very clear, good range etc. Then sometime later, possibly after I installed my sterling charger it's developed an interference that sounds like the alternator, it's certainly rev dependant.
Earth is good, set connected direct to liesure battery.

Only thing that cures it is having the squelch up so high that it destroys transmission.

Also seems to be ok for first 5-10mins of use but then interference sets in.

Any ideas how to solve it, it drives me crazy.