Transmission1

Thinking about it, if used by securicor then not sure they would use the cb frequencies as anyone could listen in. Still trying to get the channel display to be bright st present, it is there as mentioned but really really dim.

3pinplug wrote: ↑16 Apr 2022, 18:47 Thinking about it, if used by securicor then not sure they would use the cb frequencies as anyone could listen in. Still trying to get the channel display to be bright st present, it is there as mentioned but really really dim.

Not sure if it WAS them, but a well-known company nevertheless, but it was just so they could make some money fitting them for people, not to use them themselves.

I haven't got any CB mag's at all now, but someone might be able to find the article (about 2 pages long from memory).

On the channel display board there is the resistor IC for the LED display (not sure of its correct term), I'm sure I remember seeing somewhere that if faulty you can replace the IC with several normal resistors. It says "1.0K ohm" on the IC itself, is that the value I would need each resistor to be?

Also when I desolder the resistor IC assuming i just span across the holes left by the IC with the individual resistors?

I couldn't tell you about resistor values, but I do recall someon on here going on about a bank of resistors sorting out the display a few years back (I can't recall the exact number but between 12 and 20 I think), so perhaps have a search on here

Some progress at last - well sort of!!!

I tried testing the LED display using my DVM in diode test and none of the digits would light so replaced the display. I know have some illumination at normal brightness Ch1-9 but hit Ch10 or above and the display goes dim again. Also have some dodgy joints as movign the channel board appear to cut the power to the display, its very intermittent. Also in the pic it shows CH3 but one digit is out, hence thinking resistor IC.

Resoldered all of the joints on the channel board but no difference. Still wondering if the resitor IC may be a problem but also think i may replace the 2 x ribbon cables going to the display, i did continuity test all the wit=res in the ribbon cable and they showed as ok but as the fault is intemittemt i may have been unlucky.

Has anyone ever replaced the ribbon cables before, I know there is the grey sleeved ribbon cable for PC's but that from memory is thinner , what have you guys used in the past to replace the ribbon cable, arrowed in the pic?

That LC7120 board with external oscillator for the 15mhz crystals is interesting, does it still have the LC7137 and U.K channels ? Or is it gone now? I’m guessing it is no longer there, you could add a 15.810 for high band as well

Hi Nick
Unfortunately i havent tested the frequency yet as still trying to sort the display. When i sort the display i will let you know what it does for sure.
I am currently only have the following voltage on the 2SC1383 on the Channel board (PTSW155AOX) :-
Emitter = 4.79v
Collector = 13.74v
Base = 13.74v
The emitter pad is on its own, have changed the transistor but still low on voltage, with the pad on its own anynoe know why i havent the 13v i need for the display here?

Hello

on the ptsw155aox board trace the wires to the cybernet board there should be a Low-Frequency Power Amp on the selector board which supplys the leds maybe its damaged or dry jointed

viewtopic.php?style=7&p=269766#p269766

@+
Claude

Hi claude
ReAd the post , thanks for the link, it refers to removing some wires from point a&b but no pics as to which ones they are which is a shame as is a very similar issue.

Is the 2SC1383 on the channel board the low power amp?

Fingers crossed I am there!

I found the 2SC1383 was fitted the wrong way round hence the low voltage, have fitted a new one the right orientation I now have 13V going to the anode of the display not 4v! Replaced the 2SC1383 before and put it back as it was, didn't query the orientation as it matched the silk screen, but it actually goes the other way - result right voltage! (as shown in pic)

Now to the final issue, I had fitted a new LED channel dispaly Part no.KEM-3622-BSG and although it illuminates - all the numbers are jumbled it, I have attached two pics what It shows for Channel 40 and Channel 1 below.

Can anyone advise on the part number of replacement green LED channel display for the cybernet 3000, its smaller in size compared to the normal ones. After testing the original display (lots of segments out) vs the KEM part coresponding pins illuminate different segments, hence why i think a new display and bingo problem solved. I checked the channel codes arriving at the channel selector board from the PLL and they are all correct.

Hope someone can point me in the direction of the right display.

found this in a box of bits
your more then welcome to it
just send me a pm with your address and i will pop it in the post

Pm sent, many thanks!!!