k9rzz
Member
What have you got? Use coax ideally, but use whatever. Just be sure to couple it through a capacitor to isolate voltages from the radio and your audio source.
Collins R-392?
- Thread starter mfn002
- Start date
- Status
Okay. So what kind of capacitor do I need or could just any cap do?
Well, I lost that other R-392 I was bidding on, so I guess I'm stuck with this thing. I wish I had some of the equipment necessary to test this thing, but I don't.
Progress Report
I just finished putting the radio back together after I took out the IF and audio subchassis. Upon testing, I noticed that the bandwidth control was working, as was the volume. Still no RX, though. However, I did notice that there were occassional pops and snaps in the static when I adjusted the frequency. Also, the volume level changes when I move the bandwidth control.
I just finished putting the radio back together after I took out the IF and audio subchassis. Upon testing, I noticed that the bandwidth control was working, as was the volume. Still no RX, though. However, I did notice that there were occassional pops and snaps in the static when I adjusted the frequency. Also, the volume level changes when I move the bandwidth control.
ridgescan
Member
You could be causing further damage at this point-if you have capacitors way out of tolerance or flamed resistors or shorts you could be sending further damage down the circuits. I seriously would try and contact a radio restorer to recap and replace bad components in there if you plan on keeping it. BTW any news on the r71a? Just cannot get liftoff there huh?
k9rzz
Member
Howz the tube situation?
Ridgescan, it's been way too hot to try any outdoor antenna with the R71A right now (the heat index has been upwards of 105). As for the R392, I seriously doubt I'm creating more damage because now it seems the audio problem has fixed itself. All I did yesterday was to remove the audio and IF decks (the ones on the bottom) to see what kind of caps I would need if I decide to replace them. I don't know exactly what I could have done to make it work again, except for realigning the gears on the spidle that controls the bandwidth. That seems to have done something, because now the static changes tone and volume when I adjust the bandwidth switch. I ran a test procedure described in the manual to check whether both the audio and I.F. stages were functioning. You have to see if the rushing sound reduces in volume when you adjust the bandwidth control from 8 kHz down to 2 kHz. To my surprise, that's exactly what happened. This, according to the manual, indicates that both stages are functioning normally. The squelch now works again, with the Carrier Level meter moving when I adjust it. Unfortunately, I can't seem to find anyone around here who could fix it for me.
K9RZZ, I can't really tell if the new tubes helped or not, but I don't think it made much difference.
K9RZZ, I can't really tell if the new tubes helped or not, but I don't think it made much difference.
Last edited:
pjtnascar
Member
It sounds like you are making some progress, in my opinion. From your pictures, that radio appears to have lots of gears and stuff. Getting those adjusted is a good idea. Have you tested voltages in the radio? From what I have read, there are several testing points built in to the chassis for easy testing. Also, have you checked and sorted out those repairs made with electrical tape and wire nuts?
Unfortunately, the frequency control knobs are somehow stuck to their shafts and I can't seem to remove them, and I'm afraid to force it too much. If I could remove the front panel it would make life a whole lot easier. On another site's forum, someone mentioned that I check the crystal oscillators. How would I go about doing that? On that same forum (antiqueradios.com), people have also been telling me that the caps are NOT prone to failure and that replacing them would likely NOT do any good. Here's a link for the conversation I have been having there (screen name is MIKE511986).
http://antiqueradios.com/forums/viewtopic.php?f=5&t=200577&start=0
http://antiqueradios.com/forums/viewtopic.php?f=5&t=200577&start=0
Last edited:
NOTE: I decided to copy this message I posted on the Antique Radio Forums to here, in case anyone here knows what's going on.
Yesterday, I once again opened the radio up. This time, I noticed that one of the slug racks wasn't moving. After some further examination, it appeared that the clamp holding the drive gear to the shaft had come loose. I tightened it, and it started moving normally. I also noticed that another slug rack was binding at the very top of its movement, and wouldn't go back down. Oddly, it was only the front end that did this. The other end goes down normally. It seems that something is holding it up. It didn't seem like a lube issue because it took some force to get it to return to the down position. I couldn't see any sort of bend or deformity in the frame, so I don't know what is going on there.
After adjusting every slug plunger, I still haven't picked anything up. I do notice that occassionally there will be a burst of static that starts off faint and then builds up in volume before suddenly disappearing. I also noticed that on certain frequencies there is a louder hiss, but nothing else. When I turn on the BFO, there's a loud squealing sound. The odd thing is is that I'll find this hiss as I go up and down the frequency dial, but seems to vanish if I try to zero in on it. Then it'll start over again on either a lower or higher frequency, and again goes away if I try to zero in on it. I am not exactly sure what this means.
UPDATE:
I fixed the slug rack problem (something was out of alignment). Now, every time the PTO hits the 900 kHz mark, I'll get loud static and, suddenly, everything starts working. I noticed that there is a change in static every time I touch the antenna, and the ANT TRIM switch starts working. Any other frequency, and it stops working again. An interesting note is that it's only the kHz and NOT the MHz. I tried adjusting more of the slugs, but that didn't seem to do much except make the static quieter on the 900 kHz band.
ANOTHER UPDATE:
Apparently, it isn't the PTO that's working here. It appears that it's just the slugs. I spun the PTO a couple times with my hand and it didn't appear to make any difference. Oddly, the volume of the 900 kHz static changed every time I adjusted the MHz dial. The exact frequency that the static is the loudest on is 955 kHz. It is also the strongest on 11955 kHz. I also noticed something else with the PTO: despite having the radio on for 10+ minutes, the tube on the PTO assembly wasn't even warm, while all the other tubes were very hot. However, disconnecting the wiring harness to it caused the static to stop.
Yesterday, I once again opened the radio up. This time, I noticed that one of the slug racks wasn't moving. After some further examination, it appeared that the clamp holding the drive gear to the shaft had come loose. I tightened it, and it started moving normally. I also noticed that another slug rack was binding at the very top of its movement, and wouldn't go back down. Oddly, it was only the front end that did this. The other end goes down normally. It seems that something is holding it up. It didn't seem like a lube issue because it took some force to get it to return to the down position. I couldn't see any sort of bend or deformity in the frame, so I don't know what is going on there.
After adjusting every slug plunger, I still haven't picked anything up. I do notice that occassionally there will be a burst of static that starts off faint and then builds up in volume before suddenly disappearing. I also noticed that on certain frequencies there is a louder hiss, but nothing else. When I turn on the BFO, there's a loud squealing sound. The odd thing is is that I'll find this hiss as I go up and down the frequency dial, but seems to vanish if I try to zero in on it. Then it'll start over again on either a lower or higher frequency, and again goes away if I try to zero in on it. I am not exactly sure what this means.
UPDATE:
I fixed the slug rack problem (something was out of alignment). Now, every time the PTO hits the 900 kHz mark, I'll get loud static and, suddenly, everything starts working. I noticed that there is a change in static every time I touch the antenna, and the ANT TRIM switch starts working. Any other frequency, and it stops working again. An interesting note is that it's only the kHz and NOT the MHz. I tried adjusting more of the slugs, but that didn't seem to do much except make the static quieter on the 900 kHz band.
ANOTHER UPDATE:
Apparently, it isn't the PTO that's working here. It appears that it's just the slugs. I spun the PTO a couple times with my hand and it didn't appear to make any difference. Oddly, the volume of the 900 kHz static changed every time I adjusted the MHz dial. The exact frequency that the static is the loudest on is 955 kHz. It is also the strongest on 11955 kHz. I also noticed something else with the PTO: despite having the radio on for 10+ minutes, the tube on the PTO assembly wasn't even warm, while all the other tubes were very hot. However, disconnecting the wiring harness to it caused the static to stop.
k9rzz
Member
Interesting.
Well, like it or not ... you're slowly becomming an expert on the R-392.
Well, like it or not ... you're slowly becomming an expert on the R-392.
Interesting.
Well, like it or not ... you're slowly becomming an expert on the R-392.
Definitely. I'm getting the Technical Manual tomorrow, so I hope it will help (somewhat).
Well, despite having both the tech manual and a frequency generator, I haven't been able to get anything out of the radio. Oddly, it seems to work when I hook the antenna directly to J808 on the PTO connector board. I did (briefly) get it to receive a local AM station, but that was it. Unfortunately, this has gone WAY beyond my level of expertise. As a result, I have given up on it (for now). I am now the proud owner of a (depending on which end you look at) either a Stewart-Warner or an Electronic Assistance Corporation R-390A/URR. Yes, I know about the caps and the power-up procedure. I've ordered new caps and a variac.
k9rzz
Member
Nothing wrong with taking a breather from the project. Props for sticking it out this long! When you find the problem you'll say "Doh! Why didn't I do that first???" :^)
k9rzz
Member
Just curious ... any update on this that you'd like to offer?
for mfn002
Michael,
You have a world class radio and I really think you will need some help to get it going . I suggest you join a local ham radio club and find somebody with advanced HF radio technician experience to troubleshoot logically from the Audio back towards the RF section. You have a very fine radio worthy of a lot of love and care. Seek some high level help.
Cheers John A
Michael,
You have a world class radio and I really think you will need some help to get it going . I suggest you join a local ham radio club and find somebody with advanced HF radio technician experience to troubleshoot logically from the Audio back towards the RF section. You have a very fine radio worthy of a lot of love and care. Seek some high level help.
Cheers John A
BDM123
Member
Mike try posting your issue in this forum in the "communication receivers" section. Very avid & knowledgeable boat anchor collectors and quite a few own and have restored this set. This site is also extremely active.
Antique Radio Forums • Index page
Antique Radio Forums • Index page
majoco
Stirrer
The radio wants 3amps, your power supply is capable of supplying 6.5amps, therefore no problem.
24volts used in vehicles, 28volts used on aircraft, no problem.
Your finger is not an antenna - get a long bit of wire onto the antenna terminal. Try tuning around 7300kHz in the evening - lots of broadcast stations there.
Not necessarily. Manufacturers buy tubes in vast numbers and go for the cheapest suppliers. Somebody selling 6SK7's this week at $1.45 may be undercut by another seller at $1.40 next week!
Persevere - you'll get it going in the end - think of it as a challenge. Just don't let the magic smoke out that makes it work - but you can get some more smoke.....
Last edited:
KF5UFA
Member
Great thread! I picked up some info I can use for restoring that R-390A (Very similar boatanchor) that I just bought (For $350!!!!).
mfn002, keep us updated on your 392.......I'd like to hear how it's going.
mfn002, keep us updated on your 392.......I'd like to hear how it's going.
Gave up, bought one that actually works (a Stewart-Warner). As for the first one, it, as far as I can tell, is completely dead. I'll probably use it for parts or something. Unfortunately, it also seems the new one has a problem too. There is almost no reception below 2000 kHz. There is an AM station broadcast tower only a few miles from my house (it is owned by the company that I interned for). I can't even pick that station up--it keeps fading in and out.
I also have an R-390A (an EAC model). It also has some issues--namely, it won't receive anything. Everything seems to work fine with the exception of the not receiving part. Even with it hooked up to a signal generator, I can't get anything. When I got it, the RF cable coming out of the VFO unit was cut for some reason. I replaced the VFO unit, but it didn't help anything. I've had it sitting in my closet since September, and I'll probably pull it out again and try to get it to work after I graduate next month. I suspect the RF slugs might be out of alignment or something.
- Status
Similar threads
