Transmission1

Thanks

Ok, so new 3 way switch added as below. The channel display will only work when the band switch is set to HIGH. MID or LOW and is goes off.

Anyone spot a mistake?

(Colours are factory correct)

Looks to me like your EARTH wire is wrong , and you're shorting out the 8V supply . It should be on pin 8 by itself . Pins 9 , 10 ,and 11 should be jumpered together with the yellow SFT wire connected to any one of those .

That gives +8V to SFT on LOW and MID , and it grounds it on the HI band .

Sammy

You're dead right.... My bad for not checking my work.

So now have the radio keying LOW and MID but not at HIGH. There is no power from the radio nor is it receiving um... First things first just got to figure out the lack of a HIGH band.

VCO might need adjusting slightly. ?

Sorry when I say lack of HIGH. I have no TX (LED to red) in HIGH, whereas it's there in LOW and MID, simply keying. That's on top of TX/RX issues

It was a birds nest of 5 band/UK40 mod... Along with all sorts of other diodes randomly not connected!

OK spent an age on this today and no joy with the High Band. Leave aside whether the final is blown, it will not key the LED in HIGH to TX.

Any ideas?

Sounds to me the band switch is still not right, Test MX3 wire on high band and see if it has 8v or better still Take the 8v wire off the band switch and connect it directly to MX3 and see if you have high band, If so then its your band switching, There are 4 pins per section on the band switch and the input pin to each section is a sort of T shape, 8V goes to the T shape pin and then you can check which pin is for what band by using a multimeter.

I dont have my camera handy so this is a quick crude drawing of what the band switching should look like on that type of switch, You can easily test which pin is for what band with either a continuity test, One probe to T pin and other probe test each other pin on each position, Or 8v to T pin and test band pins for 8v

His picture for the bands looks good . 8V on Pin 18 , with pink , violet and grey on 14 , 16 and 17 . Still sounds to me as if the VCO isn't locked on the HI band , but it would be a lot easier to diagnose with the radio in front of me .

Before you adjust VCO, Do you have 8v on the MX3 wire when on high band position ? Does High band lock on Channel 1 High band ?

OK - Something is a miss

GREY - LOW (MX3)
PINK - MID (MX1)
VIOLENT - HIGH (MX2)

All fine with 8v but clearly in the wrong order based on the previous info you gave me

Black Spirit wrote: ↑19 May 2018, 13:13 You can get three way band switches from ebay [https://www.ebay.com/itm/2pc-Rotary-Swi ... 100623.m-1] MX1=LOW BAND, MX2=MID BAND, MX3=HIGH BAND,

It is indeed one of those overseas switches.


My switch is wired as below

Hello

The Service Manual Superstar 360 FM are here

http://www.cbradio.nl/superstar/Service ... 010_FR.pdf

http://78roger.free.fr/president/manuel ... _360fm.pdf

@+
Claude

As Sammy says its difficult to know whats going on without actually seeing it.

I don't have any radios with me to use as a reference , however , you can see where the wires go to the pcb from the wiring diagram that was posted by Tim .

Otter wrote: ↑17 May 2018, 10:25 It's not a picture, but the wiring is detailed in the service manual for the Cobra 148GTL-DX on CB Tricks.

http://www.cbtricks.com/radios/cobra/14 ... g35_36.pdf

I've marked the colours on this one .
Sammy

Thanks Sammy it matches the diagram... Well... Nick Might you be able to have a look at it please??? Won't be for a couple of weeks until I'm back?