Anyone made a CB (cough) SWR meter?

Discussion in 'Wireless & RF Design' started by Little Ghostman, Jan 13, 2014.

  1. Little Ghostman

    Thread Starter Member

    Jan 1, 2014
    I have just got my first radio :D, I have googled for homebrew SWR but havnt found anything that makes much sense, has anyone actually built a good one? I am after a design I can incorporate into a multi purpose meter.
    I found this one
    but not too sure how good it would be. So maybe my question should be, how do I know a good design from a bad one :D, the first I want to make will be analogue (I have a cool meter I want to use), then I want to make one with a pic :O

    Thank you
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    The construction method looks valid. It might be that the mighty three watts of RF from a CB might not drive an insensitive meter, though...

    The ARRL Radio Amateur's Handbook usually has a circuit for a SWR bridge.
  3. vk6zgo

    Active Member

    Jul 21, 2012
    It may be a bit insensitive at 27MHz,as he is referring to using slightly more at 28MHz.
    Remember,in Oz,we have two CB Bands---27MHz & around 477MHz.
    Most CB work is done on the latter.

    Why not build it ,anyway,& try it?
    Doesn't look like a lot of work.

    If all you wanted was a 27MHZ one,I'd say just look around swap meets & the like--if the UK was anything like OZ,there were thousands of them sold.

    I have two "CB" style SWR meters.(the cheapest one,originally sold as "faulty" is quite accurate,whereas the other looks good,but is crap!)

    They are a bit different in construction,in that they use a "trough" with lines through it,instead of a board with lines in the form of tracks.
  4. alfacliff

    Well-Known Member

    Dec 13, 2013
    the rsgb handbook should have one for the 400 mhz band. for that band you have to use specialized wireing and construction, thats the radio socioty of great britain, the british version of the arrl. also the arrl vhf uhv handbook has designs.
  5. bertus


    Apr 5, 2008
  6. Little Ghostman

    Thread Starter Member

    Jan 1, 2014
    The output is 5W ok not huge :D Its a start, I am going to be starting my license course for amateur radio next week, the club I have joined does a 6 week course. The cb I got was cheap as I had a low budget, but it has the advantage of easy conversion to 10 meter, ok 10 meter isnt great, but at my age these things take time to build up! i am busy selling led cubes and a couple of other things (xbox light mods mainly) at school. Isnt going to make me rich, but second day back to school today and so far made £20(profit) :D.
    I know CB is looked down on (shame) but its my only way into radio! is it possiable to amplify the signal in the SWR meter? I have been reading conflicting things about VSWR and SWR. As always the net has many takes on the same thing
  7. alfacliff

    Well-Known Member

    Dec 13, 2013
    here in the US, most of the "cb" swr meters use a 200 micro amp meter. I have seen one design that used a piece of coax, about 8 inches long, with the outer jacket stripped off and two wires fed under the shield braid used as a directional coupler then the wires are connected the same as the bars in the usual 3 paralell bar swr pickup. I have no idea where the artical came from.
  8. debe

    Senior Member

    Sep 21, 2010
    This is a SWR meter used on 27Mhz back in about 1978, & a few pics & circuit of it. I used to use it for tuning 27Mhz aerials for CBs. There must be heaps of these around 2nd hand going cheep these days, as 27Mhz CB is almost unused here in Australia.

    Active Member

    Aug 8, 2011
    The circuit that "debe" presented is probably one of the simplest there is and most versatile, it can be modified easily for VHF and / or UHF simply by changing some component values .
    Another good one would be the "DRAKE W4" (easily found on the web) circuit.
    My favorite is the "COLLINS 302-c3", basically the same as the "DRAKE" but a little harder to find the original type part's for in today's world.
  10. Little Ghostman

    Thread Starter Member

    Jan 1, 2014
    thanks guys, interesting stuff! I am looking at other ways at the moment, I might sell some stuff and go for a antenna analyzer. Working on making a Dipole at the moment
  11. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    There are countless good designs based on the MONIMATCH coupler, described in nearly any edition of the ARRL handbook.