Copper Talk » Ask The Tech » Radio's Mobile » Archived Messages » 2950 Looses recieve and drifts off channel. « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Macgyver
New member
Username: Macgyver

Post Number: 1
Registered: 11-2005
Posted on Sunday, November 06, 2005 - 6:02 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Thanks everyone for looking over my post. My problem is two-fold so I will split this post up.

1)I have an older (about 10 years) 2950 that will intermittantly loose recieve completely. It will not transmit when it is in this state either.

As expected, a good smack usually sets it straight again. It does this with or without a microphone plugged in, so it is not a mic problem.

2) Also, it will sometimes drift down a channel for no reason. For example, I'll be listening to a conversation on 38 and it will disappear. I tune down to 37 and there's the conversation again. A few minutes later it will find itself back on track. It's a perfect 10k shift, I don't even have to touch my clarifier if I'm on SSB. It just doesn't always match the displayed channel. I do not know if this also affects transmit.

Thanks for all your help!
Top of pagePrevious messageNext messageBottom of page Link to this message

Outkast
Member
Username: Outkast

Post Number: 78
Registered: 9-2005


Posted on Sunday, November 06, 2005 - 6:52 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hmm I am no expert but on my old cobra 29 if I switched channels and the knob did not stop completly in place I would lose recieve and could not transmit, and a light tap on it would jar the knob just enough to get it back on channel. Not saying this is what is wrong with your 2950 but deffinately something to look at.

Outkast

CEF 650
Top of pagePrevious messageNext messageBottom of page Link to this message

Patzerozero
Senior Member
Username: Patzerozero

Post Number: 1843
Registered: 7-2004


Posted on Sunday, November 06, 2005 - 7:44 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

when 'the smack' corrects a problem, even if only til it needs another, the problem is almost always a poor connection, usually a bad solder joint. only way to find a bad solder joint is to shine some light on the subject & look for something that's not right and/or break out the soldering iron & start hitting everything involved with the area giving trouble. next time you have trouble, see if you can turn the radio over & get covers removed or at least ready to be removed WITHOUT jarring the radio enough to simulate 'the smack'. disconnect power & hit it with the soldering iron, power it up & see if it comes to life. i've retouched an entire main board before finding a problem...on an auxiliary board

as for your 2nd problem does it actually 'drift down' slowly, or does it BOOM go down 1 channel? if it just changes 1 channel, that too could be a bad solder joint, even the same one, somewhere on the channel selector, board, etc.
Top of pagePrevious messageNext messageBottom of page Link to this message

Macgyver
New member
Username: Macgyver

Post Number: 2
Registered: 11-2005
Posted on Monday, November 07, 2005 - 1:32 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Yeah, it just GOES down a channel, and as I mentioned, a perfect 10k shift. It just pops to another channel while the LCD display stays in place.

As for the intermittant, I've been going NUTS trying to find it. Have had the thing sitting on the bench, covers off, many times. Let it screw up, played with all the mic wiring, tightened the connector (might need it for ground, IDK) etc.

I'm guessing it's something on the board, perhaps a relay or transistor that would normally switch between xmit and recieve that has a bad connection. I was hoping someone here has experienced that before, it's driving me nuts!

Thanks for the replies, keep 'em coming!

73's!
Top of pagePrevious messageNext messageBottom of page Link to this message

Tech833
Moderator
Username: Tech833

Post Number: 1084
Registered: 8-2002
Posted on Monday, November 07, 2005 - 10:09 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

"I'm guessing it's something on the board, perhaps a relay or transistor "


It is not a component, you have a bad solder joint. As mentioned above, break out the soldering iron and some flux and hit EVERY solder joint in the affected circuit. Eventually, you will get the culprit. Sorry, no 'quick fix' for you, just the right onw that will solve it.

If you do not feel comfortable doing this, I'll bet Copper can do it for you.

Oh, keep in mind, the radio may possibly need to be realigned after you perform this procedure, but likely not. Do not be alarmed if after solving the intermittant that you find the alignment off slightly.
Top of pagePrevious messageNext messageBottom of page Link to this message

Macgyver
New member
Username: Macgyver

Post Number: 3
Registered: 11-2005
Posted on Tuesday, November 08, 2005 - 11:37 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Thanks again for the replies.

What I had meant by "something on the board" was something's attatchment to the board, as in, something on the board is loose, as opposed to it being a direct wire on the microphone jack, as I've already confirmed those are OK. I was just hoping someone could give me some direction as to what components I should check.

Yeah this is definately an odd problem, I was pretty sure I was on my own for this one but it never hurts to ask!

73's!
Top of pagePrevious messageNext messageBottom of page Link to this message

Rippedradio
Intermediate Member
Username: Rippedradio

Post Number: 121
Registered: 7-2002
Posted on Wednesday, November 09, 2005 - 7:39 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

there is an 8 volt regulator attached to the right side of the radio the very first ic you see on the right side with the speaker side up! this regulator controls the rx and tx and the solder joints become loose over time from mobile use or rough handling! remove the solder from the ic and resolder it to the board with fresh solder! should fix your problem may fix both!!
Top of pagePrevious messageNext messageBottom of page Link to this message

Macgyver
New member
Username: Macgyver

Post Number: 4
Registered: 11-2005
Posted on Wednesday, November 09, 2005 - 11:59 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Thank you very much Rippedradio!!! This is exactly the type of answer I was hoping to find! I'll start my search there, no fun checking 100+ components with absoloutely no direction what so ever....

73's
Top of pagePrevious messageNext messageBottom of page Link to this message

Kid_vicious
Advanced Member
Username: Kid_vicious

Post Number: 814
Registered: 9-2004
Posted on Thursday, November 10, 2005 - 1:02 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

macgyver, i bet its tough to ask questions when you use a screen name like macgyver eh?

welcome to the forum! since you are new here you probably dont realize that the two people who suggested that you use your soldering iron to heat up solder joints until you find the problem, are two of the smartest guys on this forum; and we have plenty! their ideas are exactly what you should do.

while i agree with rippedradios idea as a good place to start; if thats not the problem, you're right back at square one. at that point, since you've already got the soldering iron hot; you might as well poke around the radio looking for trouble spots.

i like to use a chopstick to poke and push on the PC board. then use the soldering iron all around the area where the problem was found.

also, a cold solder joint on the voltage regulator will not cause a 10khz jump. if the radio was used in a mobile stting, the bracket bolts tend to flex the chassis enough to crack the board.
again, pat and tech833 have LOTS of tech experience; and in my humble opinion you should thank them for their help, and try their ideas.
just me two cents worth,
matt
Top of pagePrevious messageNext messageBottom of page Link to this message

Macgyver
New member
Username: Macgyver

Post Number: 5
Registered: 11-2005
Posted on Thursday, November 10, 2005 - 7:11 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Kid vicious, thanks for the reply. Yes, I suppose with a name like MacGyver asking for tech help can be tricky ;) I'm very much a "fix anything" type, but electronics are surely not my strongest asset unfortionately.

I've poked around the board enough to realize that Tech833 and Pat are without a doubt very knowledgable, and of course their insight is always appreciated, as is anyones. I agree, checking and re-soldering all of the connections is probably a good idea, particularly on the Ranger which is notorious for being damaged by long term vibration. But having that starting point of a specific transistor gives me something extra; the ability to test and confirm my repair. I may very well go over the entire board for good measure, however I just define a problem before I fix it, rather than go the "try everything" route first, I prefer to save that as a final measure.

Again, thank you everyone for your help. All of you have had good suggestions and if anyone feels that their insight was not appreciated, this is not the case. You all have been helpful and for that I thank you.

73's

Pete
Top of pagePrevious messageNext messageBottom of page Link to this message

Kid_vicious
Advanced Member
Username: Kid_vicious

Post Number: 819
Registered: 9-2004
Posted on Thursday, November 10, 2005 - 11:45 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

right on macgyver,

i dont think anyone feels slighted, i was just trying to point out that you may not have known how lucky you were to get a response from those two guys. sometimes, we end up more confused AFTER we read all the advice given in these threads.

i do agree with your troubleshooting approach, but in this case, i think you're going to end up having to poke around. seems a very strange problem, but the good news is, strange problems often have simple solutions.

good luck and be sure to post your results with many details. we mark these down in our mental databases for future reference.
matt
Top of pagePrevious messageNext messageBottom of page Link to this message

Semi
Junior Member
Username: Semi

Post Number: 10
Registered: 7-2005
Posted on Friday, November 11, 2005 - 12:31 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

You are getting good advice from all. You just have to be patient. I had a 2950 once that drove me to drinkin!!!!!!! Had to use a plastic tool and pretty much giggle every part on the component side to find the bad spot. This after I touched up a lot of solder joints on the board side. Turned out the poor solder joint was under one of the shield plates on the bottom of the board. Believe me it took a long time to find that one.
Just thought I'd chime in.

Semi
Top of pagePrevious messageNext messageBottom of page Link to this message

Macgyver
New member
Username: Macgyver

Post Number: 6
Registered: 11-2005
Posted on Saturday, November 12, 2005 - 11:59 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Thanks agian Kid vicious, and also to you Semi for your replies.

I'll be looking into this over the weekend, and by all means I will post the results. You all have given me great advice, hopefully my findings can be your advice sometime in the future.

73's

Pete
Top of pagePrevious messageNext messageBottom of page Link to this message

Shady
Junior Member
Username: Shady

Post Number: 49
Registered: 12-2004
Posted on Friday, November 25, 2005 - 10:28 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Macgeyver,

I had all kinds of problems with my first generation 2950(too many to list all of them), One of the biggest was the Mic dropping out and then a good smack would usually bring it back and fix all the other problems, but over time it progressivly got worse, well, It turned out that the Display board wasnt making good connections with the rest of the radio, The display board plugs into the rest of the radio by a bunch of pins that are about 1.5" long.... Not sure exactly how many are there, but somewhere around 25 of them... If you pull off the face plate, there are 4 screws that hold the display board and button board in place, Unscrew those and gently pull the display board out, add just a touch of solder from the tip down about a half inch to each pin, this will make the pins a little wider and make them fit in the port tighter therefore helping to make a better connection..... If there is a loose connection with those pins, it can cause all kinds of unusual problems.... That display board and button board a are a key part of everythig that works inside the 2950, I did this to mine and it straightened out every one of the problems... Now the radio works like brand new, I cant tell you how many hours I spent poking around inside the radio trying to find the cause of the problems.... The port the pins slide into may be getting worn and loose inside and therefore not making a tight connection with the pins....

William
CEF#463 Northwest Florida
Top of pagePrevious messageNext messageBottom of page Link to this message

Macgyver
New member
Username: Macgyver

Post Number: 7
Registered: 11-2005
Posted on Sunday, December 04, 2005 - 10:03 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Awsome Shady!!!! Finally got the chance to take it apart and screw with it, so I will check that too.
Top of pagePrevious messageNext messageBottom of page Link to this message

Macgyver
New member
Username: Macgyver

Post Number: 8
Registered: 11-2005
Posted on Sunday, December 04, 2005 - 11:29 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Found the TX/RX problem!!!!!!!!!!!!!!!!!!!!!!!!!

Answer was in this thread.... http://www.copperelectronics.com/cgi-bin/discus4/board-auth.cgi?lm=1112161182&file=/34/78965.html

Just have to re-solder the connections on IC5. If I push/pull the chassis (covers off) apart and together I can duplicate the problem. Sometimes just touching the chassis next to IC5 will cause the recieve to flicker. Simple fix!

Thank you again everyone for giving your suggestions. There is no wrong advice, just good advice for the future :-) I've learned a lot about my radio from this thread.

I must say this board rocks, I was dangerously close to throwing this radio out of the darn window the other day.
Top of pagePrevious messageNext messageBottom of page Link to this message

Road_warrior
Senior Member
Username: Road_warrior

Post Number: 1019
Registered: 7-2004
Posted on Monday, December 05, 2005 - 12:30 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Glad you found the problem!
Sometimes if you can't find the answer here,
go to Website (Ranger USA) and they give tips
on solving problems with certain Ranger radios. And other interesting installs that can be made.
You can also e-mail a Ranger Tech with questions
to your problem. Have a great day!

Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: