Search found 62 matches

by euhara
Tuesday 5th Sep 2017, 15:31
Forum: CB Radio Repair and Troubleshooting
Topic: rci2970n2 bad ssb tx modulation
Replies: 0
Views: 1447

rci2970n2 bad ssb tx modulation

board number ept695015a
sounds like it is in both am and ssb dont remember which trannies do the switching.
also volts don't go up when switched from am to ssb.
any help appreciated.
Thanks Jim.
by euhara
Sunday 1st Nov 2009, 6:06
Forum: CB Radio Repair and Troubleshooting
Topic: Broken RCI 2990dx
Replies: 1
Views: 2352

Re: Broken RCI 2990dx

Can anyone help with this problem on this 2990dx RCI radio Main board number EPT695011A? Got a new CPU and that helped, now trying to adjust the VCO's at 24.890 Mhz neither L13 or L14 will do anything. Pin 15 of IC2 and TP10 has 5.00 volts and both should be around 2.00 volts. Can anyone tell me wha...
by euhara
Thursday 15th Oct 2009, 19:52
Forum: CB Radio Repair and Troubleshooting
Topic: Broken RCI 2990dx
Replies: 1
Views: 2352

Broken RCI 2990dx

Radio Make and Model: RCI 2990dx surface mount PCB Number: EPT695011A PLL Number: Test gear available: Scope, freq. counter, DVM, solder station Symptoms: What is working: see below What has been tried: see below Did it suddenly happen ?: Bought this way Anything else that may be of help?: Hello, Is...
by euhara
Friday 4th Sep 2009, 16:13
Forum: CB Radio Repair and Troubleshooting
Topic: RCI2950DX CPU-Board-fault
Replies: 2
Views: 2406

Re: RCI2950DX CPU-Board-fault

What you are calling the hotmelt pack plugged into CN611 is the echip which gives you 11 meters. Far as your problem goes I have no idea of the cause.
Regards, Jim
by euhara
Tuesday 21st Apr 2009, 10:05
Forum: CB Radio Repair and Troubleshooting
Topic: RCI 2990 old style onboard SWR tester wont calibrate
Replies: 1
Views: 1913

Re: RCI 2990 old style onboard SWR tester wont calibrate

I like to be ignored. Doesn't look like much is happening on this forum.

Thanks anyway,
Jim
by euhara
Tuesday 14th Apr 2009, 20:13
Forum: CB Radio Repair and Troubleshooting
Topic: RCI 2990 old style onboard SWR tester wont calibrate
Replies: 1
Views: 1913

RCI 2990 old style onboard SWR tester wont calibrate

Radio Make and Model: RCI 2990 Old style PCB Number: ept295013z PLL Number: ???? Test gear available: DVM, Frequency counter Symptoms: Onboard SWR test doesn't Reach set point What is working: Everything else works What has been tried: Turned RF power up fully and tried to set calibration, will not ...
by euhara
Tuesday 13th Jan 2009, 21:49
Forum: CB Radio Repair and Troubleshooting
Topic: RCI 2950 NO RX SSB
Replies: 8
Views: 4605

RCI 2950 NO RX SSB

Only other thing I can think of is to check IC19 and C216 and C219, but I am not a tech.

Jim
by euhara
Monday 12th Jan 2009, 20:10
Forum: CB Radio Repair and Troubleshooting
Topic: RCI 2950 NO RX SSB
Replies: 8
Views: 4605

RCI 2950 NO RX SSB

Have you checked Q54 the SSB/CW audio switch?

Jim
by euhara
Friday 2nd Jan 2009, 20:24
Forum: CB Radio Modifications
Topic: MC301 & 1SS53
Replies: 2
Views: 2417

MC301 & 1SS53

Yes the 1ss53 is a proper replacement for the mc301 diode

Jim
by euhara
Sunday 28th Dec 2008, 14:38
Forum: CB Radio Repair and Troubleshooting
Topic: RCI 2990 talk back problem, can't get it turned off.
Replies: 2
Views: 2519

RCI 2990 talk back problem, can't get it turned off.

Radio Make and Model: RCI 2990 PCB Number: EPT295013z PLL Number: ????? Test gear available: DVM Freq. counter, watt meter, mod meter Solder station Symptoms: Can't get rid of talk back What is working: Everything What has been tried: Checked and tested D78,D100,D47,IC16,IC19,Q41,Q42,Q45,Q52,Q53,Q55...
by euhara
Saturday 13th Dec 2008, 15:15
Forum: CB Radio Repair and Troubleshooting
Topic: RCI 2970 Stuck in TX mode
Replies: 7
Views: 3897

RCI 2970 Stuck in TX mode

If it uses a battery test the battery.

Jim
by euhara
Friday 5th Dec 2008, 2:43
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Well I think the problem must be in IC2 one of the diodes on there must be kaput.

JIm
by euhara
Friday 5th Dec 2008, 1:05
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Then R207 must be the fault.

Jim
by euhara
Friday 5th Dec 2008, 0:46
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

I believe your answer will be that you was just joking about the problem

Regards, Jim
by euhara
Thursday 4th Dec 2008, 19:14
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Well then would you test L20 and see if it is keeping its setting properly?
Also Test L19 just for fun.

HOW about FET3 that looks like a good one to test. And don't forget to test L46.
Jim
by euhara
Thursday 4th Dec 2008, 12:56
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Seems we have been all over the PLL area and no luck there in finding the fault.
We have proven some things and disproved others. So would you tell us whether we have been close or need to go another directio, else give us a clue.

Regards, Jim
by euhara
Wednesday 3rd Dec 2008, 23:13
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

How about testing L16 is it the cause of the noise?

Jim
by euhara
Wednesday 3rd Dec 2008, 22:44
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Have you tested L17 to see if it is working properly and is it?

Jim
by euhara
Wednesday 3rd Dec 2008, 11:42
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Seems our test giver has disappeared perhaps James and myself angered him complaining about the schematic. LOL

JIm
by euhara
Tuesday 2nd Dec 2008, 11:46
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

OK I will try once more. By the way your schematic is a little worn and I haven't found a better one so I have to look in the radio to find numbers.

Is there any noise on pins 5,8,or10 of IC2?
Would you test Caps. 80,81,90, and 92 for me.
Is there noise on pin 7 of IC3 TX mode?

Jim
by euhara
Tuesday 2nd Dec 2008, 10:29
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Well then I think this is not as esay as you thought for us. I'm about out of guesses.

Jim
by euhara
Tuesday 2nd Dec 2008, 10:10
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Have you tried a known good michrophone?

Jim
by euhara
Tuesday 2nd Dec 2008, 9:50
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Would you test C172, 173, 174, and D63, and D64

Also have you checked for solder bridges on the track side and that all solder joints are ok concerning these?

Is there any noise on pins 1,6,and 8 of IC4?

Regards, Jim
by euhara
Tuesday 2nd Dec 2008, 0:16
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 20337

Test your knowledge Uniden (President) Grant PC-409

Are the voltage readings ok at IC6? Have you tested all the electrolytic caps in the audio circuit. Since it is an old radio some of these may be faulty. Perhap I should ask, is the PA working normally and is it noisy?

I'm just guessing as usual but I try.


Regards, Jim

Go to advanced search