Opinions on this 3900

A forum for the discussion of matters of a technical nature. All such activities are undertaken at the readers discretion and own risk. If you don't know what you are doing, don't blame us if it all goes wrong!
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Opinions on this 3900

Post by 310den »

I got the Super Star 3900 in an SK sale and I tested it and it seemed fine so on inspection inside I see some mods done. I assume the eeprom is for the UK 40 channels? It goes from Super Lo to Hi Hi and the UK 40 channels and seems to be on frequency when compared to another radio.
My questions are what are the wires in the photos doing? There are 2 lots that are joined together with the yellow tape on and a Grey wire that has been cut but the ends are bare, I have no idea why and what is the potentiometer for the one that has been added? Does this all look correct albeit a bit scruffy? I haven't had anything to do with CB for years so these mods are a bit alien to me so any help on this will be appreciated. See photos below.
Image

Image

Image

Image

Image
User avatar
cb4ever104
Legend
Legend
Posts: 6551
Joined: 28 Jul 2011, 21:26
Location: Alicante , España

Re: Opinions on this 3900

Post by cb4ever104 »

Doesn't look great , does it ? Yeah . Looks like a UK Eprom . The thick grey coax would normally go to the internal frequency counter , if you had one . But you don't , so that's why it's not connected on the other end . You could disconnect it and remove it if you wanted . The variable that's soldered onto the can is an unknown as I can't see where that white and orange wire goes to . The wires at the front with the tape are probably the original NB , TONE , CH9 or BEEP wires if any of the switches have been used for other purposes . The variable at the back on the RHS is the AM/FM power . It looks to have been max'ed , so I'd turn that down . The cut grey wire on J103 looks to be pin "40" on the pcb . Your pcb looks newish . I presume it's an EPT360014B ? It will be marked on the solder side . Pin 40 on the schematic I have isn't used , so it might be normal . Saying that it looks to have been soldered at one time , so I don't know . I don't have any of my radios handy , so I can't have a look for you . I've attached an image of the connector and schematic anyway . The guy who did your mod used telephone wire , instead of ribbon cable . He obviously wasn't interested in leaving the internals aesthetically pleasing .

Sammy
Capture_1.JPG
Capture_2.JPG
You do not have the required permissions to view the files attached to this post.
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
User avatar
14CS06
Top Poster
Top Poster
Posts: 1794
Joined: 04 Mar 2012, 09:15
Location: JN33LN - ALPES-MARITIMES-06 France

Re: Opinions on this 3900

Post by 14CS06 »

Hello

It is EPT360015C

Image

@+
Claude
Photo Collector CB RADIO
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Re: Opinions on this 3900

Post by 310den »

Thanks Paul. I have no idea what does what as it came to me like this. The switches on the front are: NB/ANL Off and Tone to Low for bands A, B and C and and Tone switch to HI for bands D, E and F. For UK 40 both the switches mentioned have to be UP and band knob set to E/B.
The roger beep is on permanently. CH9 does exactly that and so does the S/RF SWR CAL switch do as it should.
It would be nice to tidy this up and get things working or set as they should be. No variable power on this either. On the PCB solder side it is a EPT360015C.
EDIT, lol just beaten to it above.
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Re: Opinions on this 3900

Post by 310den »

14CS06 wrote: 24 Apr 2018, 18:42 Hello

It is EPT360015C

Image

@+
Claude
Thanks Claude, that is useful.
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Re: Opinions on this 3900

Post by 310den »

OK the wire from the unknown potentiometer is soldered on to a pin on the NB/ANL switch. top left pin as you look down from top with front facing you.
User avatar
14CS06
Top Poster
Top Poster
Posts: 1794
Joined: 04 Mar 2012, 09:15
Location: JN33LN - ALPES-MARITIMES-06 France

Re: Opinions on this 3900

Post by 14CS06 »

Photo Collector CB RADIO
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Re: Opinions on this 3900

Post by 310den »

Again.... thank you Claude.
User avatar
JollyRoger
Super Member
Super Member
Posts: 297
Joined: 27 Apr 2011, 16:31
Location: In The Shack

Re: Opinions on this 3900

Post by JollyRoger »

More likely than not the unknown pot will be for the alignment when it is switched to UK FM, the wire from the unknown pot as you say goes to the NB/ANL look at the pin on the switch below were that wire is soldered to you will find another wire that goes to the clarifier/course control. the idea of this is so you don't have to move the course control when it goes to UK FM
Regards JR

"Those who say it cannot be done shouldn't interrupt the people doing it"
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Re: Opinions on this 3900

Post by 310den »

JollyRoger wrote: 24 Apr 2018, 19:52 More likely than not the unknown pot will be for the alignment when it is switched to UK FM, the wire from the unknown pot as you say goes to the NB/ANL look at the pin on the switch below were that wire is soldered to you will find another wire that goes to the clarifier/course control. the idea of this is so you don't have to move the course control when it goes to UK FM
You are probably right as it does seem to be on frequency (needs verifying with a meter though) when clarifier is set to middle position on UK FM.
Only that one wire connected, one to earth and the other leg open. So far so good, I knew this would be the place to ask. :eh: :D
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Re: Opinions on this 3900

Post by 310den »

Very clean radio on the outside though.
IMG_5816.JPG
You do not have the required permissions to view the files attached to this post.
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Re: Opinions on this 3900

Post by 310den »

Is there a mod to change the channel 9 switch to turn the roger beep on and off?
User avatar
cb4ever104
Legend
Legend
Posts: 6551
Joined: 28 Jul 2011, 21:26
Location: Alicante , España

Re: Opinions on this 3900

Post by cb4ever104 »

310den wrote: 25 Apr 2018, 08:27 Is there a mod to change the channel 9 switch to turn the roger beep on and off?
Sure . It's a simple mod , but you'll need to know what you're doing . Remove and jumper the CH9 wires (in the off position) . Then remove the beep jumper as described here

viewtopic.php?f=29&t=51314&p=457083&hilit=beep#p457083

and wire both ends of the vacant holes to the CH9 switch .

Sammy
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
User avatar
310den
Radio Addict
Radio Addict
Posts: 946
Joined: 21 Jun 2011, 18:52
Location: West Sussex
Contact:

Re: Opinions on this 3900

Post by 310den »

cb4ever104 wrote: 25 Apr 2018, 10:41
310den wrote: 25 Apr 2018, 08:27 Is there a mod to change the channel 9 switch to turn the roger beep on and off?
Sure . It's a simple mod , but you'll need to know what you're doing . Remove and jumper the CH9 wires (in the off position) . Then remove the beep jumper as described here

viewtopic.php?f=29&t=51314&p=457083&hilit=beep#p457083

and wire both ends of the vacant holes to the CH9 switch .

Sammy
Thanks Sammy. I have a full licence for amateur use so know my way around but like I said I am way out of touch with CB radio and modding them. I think making the beep switchable is a worthwhile mod.
User avatar
cb4ever104
Legend
Legend
Posts: 6551
Joined: 28 Jul 2011, 21:26
Location: Alicante , España

Re: Opinions on this 3900

Post by cb4ever104 »

310den wrote: 25 Apr 2018, 10:54 making the beep switchable is a worthwhile mod.
Yeah . You might as well , as the CH9 switch is useless anyway . I do this mod on most of my radios .

Sammy
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
Post Reply