Panasonic RF-B65: is rotary tuning weird or is mine broken?

[modrachlan]

I had the good fortune of grabbing one of these for not a lot of coin. Used, of course, but it's in pretty good shape. I'm a little confused by the rotary tuning, though. I can use the manual tuning to tune up or down in 5 mhz increments. But of course the appeal of this radio is the SSB and its unique rotary tuning system.

When I use the rotary tuning, the frequency does not change one bit.

Also, in SSB, I cannot seem to affect the tuned frequency with the fine tune knob.

I'm beginning to think that facility is broken. But I wanted to run this by some folks who might have some experience with this radio. Might I be missing something here?

 

[Boombox]

There used to be a Panasonic Yahoo eGroup, and I know of at least one guy who was there who was very much into RF-B65's, raved about them, and seemed to know a lot about Panasonic SW radios in general, including their workings.

Have you tried shooting a little tuner cleaner into the SSB fine tuner? It appears from the glance at a block diagram I found that it is mechanical (i.e., a regular potentiometer). No idea if the rotary tuner is mechanical or optical.

 

[modrachlan]

Thank you for your reply. I tried to get some De-Oxit in there, not sure how successful it was. Now it sorta kinda works- but control is not very precise. And it jumps around in frequency now- THOUGH IN 1MHZ STEPS, not five... I feel like progress is possible.

I found the repair manual, maybe I will dismantle it, see if I can lubricate it more precisely.

 

[Boombox]

One thing to remember (as you probably already know), when radios haven't been used in a while (like years), the rotary controls can act funky at first use.

If I were in your situation, I'd look over the two controls in question once you get the radio apart, and if the rotary tuner is mechanical (i.e., not optical, and chances are high that it is NOT optical -- I can't think of any portable SW radio I've seen that has an optical rotary tuner), hit it with a bit of Deoxit.

I have an RF-B45 (the B-65's successor -- and the last radio Panasonic made in Japan, actually) and it's an excellent radio. Same basic circuitry, except the 65 has a Toshiba IF chip instead of a Sanyo one. The 65 is apparently the better of the two (according to the Panasonic Yahoo group guy), but my 45 is one of my best MW radios, and it is built like a tank inside. Panasonic built their radios excellently.

Good luck man, and hope it turns out well for you.

 

[modrachlan]

very much appreciated. thank you!

 

[modrachlan]

bad news- a thorough cleaning did not change a thing.

Furthermore, I noticed the pcb was broken near a screw standoff.

I think I may be screwed, sadly.

 

[Boombox]

I know of some guys online who use solder and wire to repair those kinds of PCB breaks.... But if the radio's surface mount, it may be very tricky to try something like that.

The only surface mount work I tried I screwed up the stereo headphone jack on my PR-D5. So much for my surface mount repair or modification career.

Surface mount is hard to work with... I think my RF-B45 is surface mount, I would guess the 65 is also.

At least you can still tune the radio with the buttons, though. And I would be it's a terrific MW performer.

 

[modrachlan]

Yeah, I will enjoy it for what it can do. I can sit on the porch and hear broadcast shortwave off the whip that other radios need the loop antenna for. So there's that!

 

[Julius568]

On the right side of the radio is a slide switch that has three settings; Lock, Slow, Fast. Make sure the switch is not in the Lock position, the rotary tuning wheel will not work if this switch is locked.

 

[pjxii]

On the right side of the radio is a slide switch that has three settings; Lock, Slow, Fast. Make sure the switch is not in the Lock position, the rotary tuning wheel will not work if this switch is locked.

The SSB fine tuning knob will still work even in the lock position, so it's more than just the main tuning dial if the fine tune doesn't do anything.

 

[majoco]

I can't think of any portable SW radio I've seen that has an optical rotary tuner

My Degen 1103 certainly has an optical tuner and spares are/were readily available - anon-co.com?

https://www.anon-co.com/Tuning_encoder/cat2010170_4030132.aspx

 

[GB46]

I've run into exactly the same problem with my Sangean ATS-909X; the tuning goes wild if I try to use the dial. It will jump around, often going backwards. I've also noticed that the dial doesn't feel as tight as it was when I first got the radio. The dial feels quite slack, and can even go out of control if I just touch it lightly.

In my radio, the fine tuning settings are toggled by a button in the middle of the dial, and holding down the button locks it. It will no longer tune the radio either fast or slow, so I've locked it for good, and am now using the up and down buttons instead, which tune in 5 kHz increments. For some reason, however, even though the dial is now locked, it still works for changing pages (i.e. memory banks), but haphazardly, so I do that with the up and down buttons, as well. The buttons are very close to the dial, so when I'm changing pages I have to make sure to keep my finger away from the dial.

In hindsight, I should have noticed a comment in a review of the ATS-909X that the tuning dial relies on a system of brushes, and the reviewer pointed out the possibility that frequent tuning with the dial will eventually wear it out. That's what happened to me, apparently, because I was not only using it for fine tuning a station, but also for browsing up and down the band.

Sangean should have had the good sense to include tuning step options for those up and down buttons, too. That way the function wouldn't be totally lost if the dial mechanism wears out. Or better still, use optoelectronics for the dial!

For sideband stations I now use only my R75, and listen to broadcast stations with the portable.

 

[Boombox]

The 909 must have been built more robust, then, because the tuning dial on my DX398 (a 909 in Radio Shack livery) was skipping frequencies and a couple shots of tuner cleaner down the side of the shaft cleared the problem.

Sorry to hear about your problem with the 909X.

 

[GB46]

The 909 must have been built more robust, then, because the tuning dial on my DX398 (a 909 in Radio Shack livery) was skipping frequencies and a couple shots of tuner cleaner down the side of the shaft cleared the problem.

Sorry to hear about your problem with the 909X.

I thought I had solved the problem by blowing into the dial; it seemed to have cured the problem, but that was probably coincidental. Oxidization is not likely to be the cause, either, because the radio is only a few months old and gets used regularly. At any rate, this is yet another example about how quality control has been going downhill these days. My Sony ICF-2002 is about 32 years old and hasn't developed any problems. The same goes for the R75, which is now 20 years old and perfectly reliable. That one, of course, is far more rugged than any portable I've owned.

My scanner is no exception to the cheap construction trend. After only a year or two of use it wound up with a completely non-functioning LCD display. My old Radio Shack Pro-2001 scanner was a tabletop radio with a metal cabinet. It was very rugged, and if I still had it today it would probably be functioning perfectly.

The little Cobra FRS radio I used for communicating with my partner to guide him while he backed our motorhome into RV campsites bit the dust fairly early, too.

Live and learn! I'm not buying any more portable radios from now on. Come to think of it, I'm not in the market for any more radios, whether they're portable or not.

 

[Boombox]

I hear you. I trust Sangean for the AM-FM's though. They are built fairly well (easy to take the back off the PR-D5 without breaking stuff), and the parts are simple and robust enough.

But the radios that have tons of features, I am hesitant about anymore. My Grundig G2 still works OK after 4 years or so but it just doesn't feel as substantially built as my PR-D5.

One thing perhaps you could try: reset the radio. I.e., disconnect all power -- batteries as well as the AC plug, for about 5 minutes or more. Some radios develop glitches if they see power for days and months. My PR-D5 developed a glitch after a month or more of seeing power, and my DX-440 glitched when fired up after a long lag (it had the AC plugged in the whole time).

It might be worth a try, if you haven't done so already. It doesn't hurt the radio, at the very least.

 

[GB46]

One thing perhaps you could try: reset the radio. I.e., disconnect all power -- batteries as well as the AC plug, for about 5 minutes or more. Some radios develop glitches if they see power for days and months. My PR-D5 developed a glitch after a month or more of seeing power, and my DX-440 glitched when fired up after a long lag (it had the AC plugged in the whole time).

It might be worth a try, if you haven't done so already. It doesn't hurt the radio, at the very least.

I'm trying that now. The memories are retained indefinitely, so I'm not worried about that. My Sony loses its memories immediately if I remove the batteries. So did the ICF-2010 that I used to have. The 2010 was a real problem, because the batteries would move around a bit in the compartment, causing an intermittent loss of power, so that I'd suddenly lose all 32 (I think it was 32) of the memories. My workaround was to stuff some padding on top of the batteries so that the lid held them tight.

As for glitches, the 909X did glitsch a few times, both on batteries and on AC, but this hasn't happened for a long time now. What it would do is suddenly reset itself while I was tuning it. The screen would go blank and the radio would shut off on its own. When I switched it back on it had put me on FM, which is where it was out of the box, and the clock needed to be reset. No big deal, because my memories were intact, but it had me worried for a while. So far it hasn't happened for at least a couple of months.

Somehow I miss the low-tech days of analog radios, despite their inaccuracies and drifting.

 

[GB46]

OK, I cut off all power to the 909X for about 10 minutes, and it has been fully reset. After powering it back up, however, there was no improvement, so the fault appears to be mechanical. Some of the SSB frequencies had been stored in memory previously after successfully fine tuning them, so they're OK, but I won't be hunting around for any new ones. Both AM and FM modes still work fine if I just use the standard tuning increments with the up/down buttons.

 

[Boombox]

Sorry it didn't work.

Have you considered contacting Sangean? Another poster on this forum had good luck getting a repair from them. Maybe it was a defective part. That can happen.

 

[GB46]

Have you considered contacting Sangean? Another poster on this forum had good luck getting a repair from them. Maybe it was a defective part. That can happen.

I've thought about it, but another (former) 909X owner on this forum told me that he had the same thing happen to his, so it looks to me like a design flaw. I'm not willing to go to the trouble and expense of shipping the unit back only to have the same thing happen again after the repair. Also, according to Sangean, the warranty is only valid in the United States. The radio works just fine for SWBC and FM listening, so I'll just use it the way it is, since SWBC is my main focus.

For SSB, including digital modes, I prefer the R75, anyway. When decoding ham FT8 signals with the 909X, the frequency column in WSJT-X shows that the radio does drift gradually downward a hertz or two at a time on the same station. This doesn't affect decoding, but it sometimes shows up in SSB voice transmissions, with the voice pitch eventually changing even with the fine tuning locked. My ICF-2002 will do that, too, but its fine tuning control is more gradual; it doesn't move in big steps. According to the schematic it's a simple potentiometer. It covers a broad range (+/- 5 kHz), however, and the thumbwheel is tiny, so it requires a steady hand. With the R75, fine tuning a sideband signal is super smooth, and I never have to retune it afterwards. Not only that, but I get to see the actual frequency, whereas neither of my portables can update the display when a signal is fine tuned in small increments.

 

[GB46]

A new development with my 909X: Since I have no access to the tuner shaft without opening up the radio's case, I hadn't tried using contact cleaner. Last night, as a last-ditch effort, I finally tried spraying it into the middle of the tuner wheel where the step button is, to see if some of it might get to the shaft. Surprise, surprise, it worked! I'm not getting the frequency skipping at all, at least so far. However, I'm keeping my fingers crossed -- which can make tuning a bit more difficult.

What I still don't understand was why the control seemed to have loosened up a lot before I used the spray, but now feels as tight as when I first got the radio out of the box. The contact cleaner contains isopropanol, isobutane and propane, but I don't think those chemicals are thick enough to do that. After all, it's not as if I used motor oil -- and what a mess that would make!