Since those sensors merely detected a short so as to create a switch function, such as a + 5 volt high or low signal. I would take an ohm meter to the underside wire output connections and see if you can detect an open and then a closed-circuit when the split tape guide 2 pieces are shorted? If you can detect a make and break function than the sensor is working. If it appears to be continually shorted even without the foil tape, you should carefully disassemble the split tape guide. It's quite possible that the fiber washer that electrically separates the two pieces may have gotten wet from the alcohol or finally deteriorated over time? It's also possible that somebody may have over tightened the screw that holds the 2 separate pieces of the sensor apart and therefore has shorted them together? Make sure that that tape guide is not physically compressing the tape so as to make the tape bow in or outward. Check and make sure that the wires connected to the tape guide sensor have not had any of the insulation worn away so as to be shorted to the chassis?

If the above has failed....The problem then would be one of the logic circuit not flipping high or low when the sensor is sending a clear signal. Certainly possible that some of those old semiconductor logic detectors have blown from static discharge? You may not be able to find a replacement part? This sad scenario has occurred even with fine pieces of professional equipment like the MCI 24 track touch sensor tape shuttle device. Based on a proprietary chip by a manufacturer that went out of business without any other company making a cross-reference replacement. Good luck?

Grooving high and Grooving low
Ms. Remy Ann David
I think my new name should be "Five Volt"? I think it's much more energetic sounding than "Fiddyscent"?

How old is this.....machine? Like an antique car(Or a new car!) any number of things can go wrong.....? Does the sensor even work? Any other problems with it? Is it properly aligned, etc? Are you putting the foil tape on the right side? The reversing mechanism is likely the last thing to worry about, for the moment......

Keep in mind that this machine was no "gem" brand new......

I see in your other post you'd like to find someone to service it. Service it with what? Where would the service person find parts for it(Other than the capacitors, all of which have probably have long-since needed replaced.)? How much would you be willing to pay a service person to get this thing in shape? It may cost hundreds of dollars, depending? Shipping the beast somewhere, alone! Again, this gadget didn't cost that much, new...

You might search the web for a service manual for it? I don't know, EBay? Bama(Search "bama manuals" - a "free" supplier of manuals for some outdated gear.)?

I applaud your efforts to keep old gear going, to some degree, but...... This is not the piece of old gear to put more than self-tried/casual effort into. And as far as getting "that tape sound" by transferring from modern, digital(Already poor quality) recordings, my advice is to try it if you like, but not to expect anything but even worse quality, with "that tape sound"(As if there were such a thing, anyway) not being decernable above the noise......

Again, good thought, though! Do what you can! Learn what you can!

TG

Wow, what a great forum this is!

I truly appreciate all the replies and helpful wisdom.

The R2R is, I know, not the King's Ransom, but it has sentimental and aesthetic value to me. I had one of these units as a kid and had to sell it for college expenses. Bought one back again on eBay purely for pleasure and I'm loving it! Here are some photos I took and dressed up in PhotoShop:

http://www.1234zzzz.com/pub/Pioneer%20R2R%20909%20A.jpg
http://www.1234zzzz.com/pub/Pioneer%20R2R%20909%20B.jpg
http://www.1234zzzz.com/pub/Pioneer%20R2R%20909%20C.jpg

The shear joy for me of the experience of using this machine outweighs the downside of the technical deficiencies of the hardware and source signal and so I accept this welcomingly.

As for refurbishing, calibrating, etc. I know that this is probably not an effective use of funds as even given a modest improvement in playback sound it would be an expensive proposition. Guess I'll try Dooby's VU suggestion if she can elaborate on how this is done.

Overall I'm tickled pink with the recording and playback sound "as-is" without even having cleaned the heads, capstan, etc. as I received it from the eBay seller. I looked at the heads and they appear visually perfect, but I still want to tear down the machine and clean it, etc.

In the end I think I won't send it out because there's no immanent need. The belt and rollers are new, so at least I'm ahead of the game this way, for the time being.

AS FOR THE AUTO REVERSE: I'll check all the tests Dooby mentioned and see what I come up with. As said, this is not a deal-breaker anyhow.

I applied the silver tape to the magnetic side of the 1/4" tape and I can see that it *is* shorting out the pole sensor visually. Next I'll need to try shorting it out, and putting a meter to it, etc. Could in the end be the logic board too of course, so I'll see, and report back.

MANY THANKS AGAIN FOR ALL THE GREAT REPLIES.

John

Again, "no prob" getting all you can from this widget, I'm sure it'll be fun(I have lots of old stuff that is, frankly, horrible - your piece is actually pretty cool - but, I like my old stuff! And, as I have time, I love to fool with it...). Just don't put much actual coin into the thing with the slightest thought that it will make it sound like anything but what it is - or was...... Keep it a personal project.....

TG

Of course, if you can find an old tech(Maybe a retired broadcast engineer?) to help out, you may really get this thing up to snuff and learn alot more, for very few extra coins and even more fun?

......aarrggghh!

Looks like I'm gonna have to dissessemble the sensor. Tried shorting it out but no reaction during play.

So, the pole is either already shorted out, or it's an open circuit to the logic board, or the logic board must be doing a Vulcan Mind Probe .

Well, I'll do this later, it's not an immediate priority.

I can always canabalize from my Pioneer RT-707 if needed perhaps, in order to get the Pioneer RT-909 up and running again.

Thanks again for you support!