Got a CB radio!

[large_ghostman]

woohoo, I am on the way to be on air! I have just won a CB radio inside my budget! Ok before you frown and diss CB, the one that I have won is easilly modded for upto 600 channels including 10meter , So I am on my way for £30 . its a starting point and a cheap way to start messing with radio, also in un modded form I can use it to transmit , its a maycom (cough) E27, with AM and FM.
Very happy bunny! Need a antenna now, and convince dad to mount it on a very long pole on one the outbuildings . was a close thing! my budget was £40 tops and I got it for £30 + £10 shipping! so bang on the money .
mad search now for schematics etc, and need to find out what PLL it uses.

 

[tcmtech]

Too bad you weren't in the US. I would send you a big package of my old CB stuff. (If I could find it all) It's not like I am ever going to play with it again.

I have three business band walkie talkies that have a range of about 2 miles. My daughter thinks talking to someone else in another room with them is a blast. At age 5 it doesn't take much to impress her.

 

[dr pepper]

Well done LG.
I still have some rigs.
I think maycom are maxon, I had a similar rig a few years back, if you google the rig as I'm sure you allready have there are loads of hacks for that model.
If I recall the rig doesnt come with AM enabled, you can enable it from the front panel but you have to hack something in the rig to get AM.

 

[large_ghostman]

https://www.normsweb.com/

you can set it for a max of 600 channels and am is 2 button presses, I also have the chip datasheet

 

[dr pepper]

It got knocked when it came out, but actually it doesnt seem a bad rig.
I even got mine to display battery voltage, so I knew when to shut up and drive off without killing the battery.

 

[audioguru]

In some countries a phone call is charged even if it is only across the street. But in North America Local calls are free with no time limit. A local call is usually anywhere in a city.
When I grew up (maybe I never did?) I called my friends for free all the time and never even saw a CB radio. Truckers (Lorry drivers?) used CB to kill the boredom of driving a truck (Lorry) and warn other truckers about police speed traps.

 

[large_ghostman]

according to dad, we didnt really get CB radio in the uk until way after the states, he said it was illegal here but in the end the government gave up, and made it legal, also apparently you had to buy a license! but you didnt have to do a test,
I have been reading today and some stuff is strange, apparently CB was meant for short range serious communication, and amateur radio was for hobby use and **** chat, when CB came out in the uk, you but a license for £10 (according to a site), but for amateur radio you have to have a test! its all bonkers back to front!
I was hoping to find loads of stuff to make, but not come up with much yet for CB, Loads for the Amateur radio tho

 

[large_ghostman]

I will try and resist the urge to tweak the power

 

[dr pepper]

CB was legalized on FM in the uk in 1981, most older legal sets have a ring with CB1981 on the front.
If you have a ham licence and you change its frequency you can go up to the limit of your licence.

 

[JimB]

apparently CB was meant for short range serious communication

In the USA in the 1950s it was meant to be for business use.
As time went by, it was also used for personal communications of all kinds, leading to the explosion in its popularity in the 1970s.

This popularity drifted across the Atlantic and the idea took hold in the UK. Eventually it was legalised in 1981, as already mentioned.

and amateur radio was for hobby use and **** chat, when CB came out in the uk, you but a license for £10 (according to a site), but for amateur radio you have to have a test! its all bonkers back to front!

No it is not!
In the UK when CB was first legalised, yes you needed to stump up some cash to buy a licence.
Eventually that requirement was dropped and the CB service became licence free.
(In the same way as the little PMR 446Mhz walkie talkies are licence free).
Basically CB and PMR446 are intended for someone who wants to buy a radio and just talk to it and has no technical interest in how it works.
In fact the radio should be "Type Approved" to ensure that is does not cause problems to other radio users.

Amateur Radio on the other hand is intended for those who have an interest in the technical aspects of radio, and talking to the radio is just an incidental activity.
Someone with an Amateur Radio Licence can use whatever equipment he wishes.
Build it from scratch, modify something, or buy ready made.
This is why there is a technical exam, to ensure (hopefully) that someone building or modifying a radio has enough knowledge to make sure that their radio will not cause problems to other radio users.

Another privelidge that radio amateurs have which is not available to most other radio users, most radio users are restricted to fixed channel frequencies, the radio amateur can use a VFO* to set any frequency he likes within the permitted bands.

* Variable Frequency Oscillator

I will try and resist the urge to tweak the power

Mostly pointless anyway.
Until you double the power, you can hardly tell the difference at the receiving end anywayl.

JimB

 

[HiTech]

I will try and resist the urge to tweak the power

Chicken Banders start off by tweaking the RF power out. Then that messes up the modulation so they defeat the ALC/AMC circuit to offset that issue and add a power mic that overwhelms and clips the audio. From there they either swap out the driver/output stage Xistors or "volt" them. Then the ever famous PLL mod gets performed to add extra channels that the chassis isn't readily capable of handling so the final step is to broadband the chassis. The whole radio becomes a mess, transmits a crappy sounding signal, and loses it's resale value from being tampered with..... not to mention it no longer meets FCC specs. (USA models).

 

[dr pepper]

As far as I understand the now CB frequency 11m did have a very serious application at one time, it was used by bomber command during ww2, only after the war the band was released.

 

[tcmtech]

Chicken Banders start off by tweaking the RF power out. Then that messes up the modulation so they defeat the ALC/AMC circuit to offset that issue and add a power mic that overwhelms and clips the audio. From there they either swap out the driver/output stage Xistors or "volt" them. Then the ever famous PLL mod gets performed to add extra channels that the chassis isn't readily capable of handling so the final step is to broadband the chassis. The whole radio becomes a mess, transmits a crappy sounding signal, and loses it's resale value from being tampered with..... not to mention it no longer meets FCC specs. (USA models).

THe guys I know who were into it big time the generation before mine liked to put Kicker amps on their systems. A high school buddies dad had a 1000 watt unit on his. He said he used to talk to people coast to coast plus Alaska and parts of South America!

Down side was every neighbor within two mile radius of his farm got to hear his side of the conversations as well so he was limited to doing his talking after the local TV and most radio stations went off the air at midnight back then in these parts.

 

[4pyros]

Glad you got it, have fun, and yes start off by checking its at max allowed power output.

 

[large_ghostman]

Chicken Banders start off by tweaking the RF power out. Then that messes up the modulation so they defeat the ALC/AMC circuit to offset that issue and add a power mic that overwhelms and clips the audio. From there they either swap out the driver/output stage Xistors or "volt" them. Then the ever famous PLL mod gets performed to add extra channels that the chassis isn't readily capable of handling so the final step is to broadband the chassis. The whole radio becomes a mess, transmits a crappy sounding signal, and loses it's resale value from being tampered with..... not to mention it no longer meets FCC specs. (USA models).

Lucky for me the radio and chip, is designed for extra channels, uk versions dont have them activated, but to activate is simply adding some jumper wires and resetting! so I dont need to mess too much, very interesting explanation of how people go about tweaking the power! the legal output here is 4W, I was having a bit of a joke about the power , I dont have near neighbours as such, but I am surrounded by farmland and having grown up on a farm, I wouldnt do anything that could mess with tractor comms etc, Dad nearly died in a tractor accident a few years back, and like now we lived in a area with little cell phone signal, so the radio got him help quickly!
I shouldn't joke about upping the power I know .
So on a more serious not the following mods are going to be done. Antenna tweaked for best performance and tuned to death in my OCD like way (learning exercise ready for A.R), turn mobile unit into more of a base station, which is mainly my way of saying get rid of internal speaker, and add external one, from there i will mess with amplifier for the speaker and concentrate on making it sound the best it can withing its limits.
Build a 13.8V 10A supply, I might be able to double the output to 20A, it depends on the transformer I have in mind. The starting point is a huge weller desoldering Transformer, output is 24V, not sure of the current as both the ones I have are different.
I would like to build the SWR meter etc as a learning exercise, and any other bits that might be useful, dad is going to get another one for the tractor also.

 

[dr pepper]

I dont think any of my mates used 4w back in the 80's, we all had burners (uk name for a linear amp), I used 10watts all the time without issues.
Beware of 'burners', they are surrounded by b.s., my 300watt rm burner put out about 20w, because the gain wasnt high enough to produce any more than that with a 4w input, and these days cb equipment is aimed at less technical folks vulnerable to marketing hype and quote overrated power fugures and use fancy names.
As far as I know noone has bee done for using excessive power in the uk on the cb band.
If you look at the channel freq chart for fm cb there are gaps, these are for the colour channels, red, green, blue etc, these are channels reserved for professional use, or they were, they are usually quiet.

 

[large_ghostman]

How does this work anyway? say I push out 10W or 20W, I see that people further away can hear me, but does in also increase what I can hear? I mean does the amp work both ways?
I doubt I would want to mess with the power, like I say I live in a area with poor mobile phone signal and people rely on these radio's when working away from base.
I would feel awful if someone couldnt get help because I was nattering and bleeding all over there channel, besides this is just a cheap way to learn radio for me, At least until I can get a license. Ultimate goal is too build a amateur radio, not sure what bands etc yet, I am joing a large local group next week, so I will get to use and look at equipment, I will decide after I have tried a few things!
I am not after the latest or greatest kit, making my own would be awsome, and means I can get the stuff together as I go along. Back to full time school next week , but I nearly have the shed back up!! I am boarding it out at the moment. I have used the digger to trench a cable (75 meters!!) so I have power to it now . Still have to fill the trench back in .
I got dad to cement some rods in the ground so the shack is now anchored to the ground . I am using a old oil drum we are modifying as a wood burner for heating, Also have some water pipe so I can put a tap in (no idea why I want running water and a sink!).
Found a old semi working p4 computer that needs a PSU, then I will have a pc . We use alot of vermiculite for different things so I will use that for insulation, also going to use sheep wool sandwiched between fine chicken wire to stop rodents. Also now coated shed with real creosote not the fake stuff! (dad can still get it ). Its starting to look really cool!

 

[dr pepper]

Sounds like my kind of shack, heat, water and pc, just the job, dont forget to build a wifi aerial from a pringles jar so you can still surf the net.
A 'burner' or linear amp only works one way outgoing, people will hear you further away, if they are operating at 4 watss you wont be able to get them further than 4 watts will get.
So long as the gear doesnt generate harmonics you shouldnt interefere with others, you'll learn about all this when you join up.
Also everything is about the aerial, a good well set up aerial with get further on 4 watts than a poorly setup naff aerial on 1kw, the latter being common.
27mhz hf acts differently than 2ghz from mobiles, if terrain is causing your mobile signal issues it'll not have so much of an impact on 27mhz, so long as your clear of buildings you should be able to get a good distance.
A really good aerial for a starter would be a dv27, they are dead easy to swr, just a twist and its done.

 

[large_ghostman]

dv27 are mobile antenna arnt they? I was looking for a fixed one, trying to talk dad into letting me put it on a pole on the house or a outbuilding, he is insisting no way as he says we will get lightening strikes as we are so high up, I am hoping for a good signal, you cant really tell on google maps, but we are higher up than the nearest town and higher than any other house for miles!
I might attach it to a huge tree we have its about 150 feet high lol, I climbed almost to the top in the summer, its some kind of spruce tree, it had a rooks nest near the top and its my job to take them down . tree climbing is my specialty

 

[dr pepper]

Dv27's work well for a home base, but you'd need a ground plane, so maybe your better with a proprietry home base aerial.