I recently acquired a SuperStar 3900 for free out of a wrecked semi. I know truckers are notorious for Mod's and do not know if any have been done to this radio. My intent was to explore available Mod's and then look at radio to see if any had been done to it. This is where the confusion started. After researching available Mod's and viewing a few schematics/board layouts, I now see there were many versions of the 3900. If anyone could look at the below and give me a clue as to which version of the 3900 this radio is I would greatly appreciate it. If anyone can tell from the below any obvious Mod's please let me know. I have noticed one possible Mod. An orange (I think) wire has been cut from J-108 and from J-304. I think these two points were once connected but have no clue why this wire would have been cut.
Thanx....
A picture of the radio front might help. also, there should be an info tag on the back with some potentially helpful data on it. Additionally, there is an etched board number on the board itself that will tell your relevant info about your model.
That number should be EPT3600xxx - with potentially the x's being 010, 014, etc.
If your radio is operating on CB frequencies, clearly the 10 meter to 11 meter conversion mod has been done.
It looks like it's one of the later radios but before the crap Ranger ones, because it's got the frequency counter socket on the back of the radio for a counter.
Does the SWR/CAL switch pull out to open the radio up to all bands and with it in you only get Mid band 26.965 to 27.405.
The ALC looks to have been turned almost off and the FM deviation looks low as well.
Zodiac...
SWR/CAL switch does not pull out.
ALC and FM deviation I am assuming are trim pots on the board??? How should these be adjusted?
HomerBB...
NWA me 2.
I did find a number (EPT360014B)on solder side of board.
Radio didn't come with mic or antenna. I did test to see if it would power up. When powered up all lights look normal with the exception of meter was not lit. I was able to hear static from speaker. I haven't invested in a mic or antenna yet until I know if the radio is worth investing in.
PhotoBucket issues, so here are direct links. End of file name is description of image.
Use this board number, EPT360014B, to locate info on your rig. It looks like mine except for color - I have gold face - and your power plug is newer. Mine is EPT360010.
I think it's worth saving, if possible.
I think the orange cut wire on the left is the beep wire, just put it to a switch so you can switch it on or off.
The other wire at the channel switch is like that in all the 3900's, that's normal.
Yes they are trim pots (adjustable VR's) but leave them alone till you've got it going then see if they need adjusting
I'd fix it.
Dave.
Zodiac/Homer
I have been able to locate only two EPT3600-14B board layout diagrams.
Rev. 1.3 and Rev.2.0. Neither of these revs show my EXACT component layout.
The direct link below is for EPT3600-14b Rev. 1.3.
I couldn't insert image as it is 4+meg.
In looking at these board layouts, I see the (orange wire) that is cut on J-108 is labeled (RB). Is this Roger Beep? If so I do not know where the other end is located at to install a switch.
Direct link = http://i744.photobucket.com/albums/xx86 ... BRev13.jpg
The other cut (orange wire) is located on the channel switch board J-304. The Channel Switch board is EPT360022Z. The below link again 4+meg. shows that the location of the cut (orange) wire is not used. http://i744.photobucket.com/albums/xx86 ... 60022Z.jpg
I have also located another cut wire (green) located on J-105 and is the fourth pin over labeled +10k. Any idea what this is for?
As I said the orange wire on the left is for switching the beep on and off.
If you hard wire the channel 9 switch for 1 to 40 you can then use that switch for switching the beep or for the +10kc, the +10kc when wired to a switch will take you up by one channel making it possible to get to the five alpha channels that the channel switch usually skips over.
Your radio has 2 switches for the bands, other 3900 have a 6 position rotary band switch giving a free switch to either fit the beep to or the +10kc.
I seem to be missing something here...
One cut wire marked RB controls Beep.
One cut wire marked +10K controls freq shift.
There are no loose wires laying around in the chassis. Without knowing where to attach the other side of the switches, this is an open circuit. Do you know where to attach the other half to complete circuit?
3900's with plugs and socket at the front of the radio are all marked, +8v, RB (roger beep), +10k etc. where all the pins connect to on the board right at the side of the sockets.
So if your radio has not been wired for the function you required just look at a schematic for the 3900 that has those functions wired to switches and copy them.
The +10kc wire goes to a switch and to +8v to move the frequency up by 1 channel (10KC's) so you can get on the Alpha channels but don't forget to switch it off when on the normal channels.
The same applies with the beep, if the beep is wired on and you want to turn it off, you only need to remove L9 (I think it is) at the front right side of the radio and put it through a switch to make it switchable.
