Pioneer RT 1020L Reel to Reel Tape Recorder

Thread Starter

EXG

Joined Jul 3, 2009
8
Yes I still like to record on reel to reel. I have three of them,different models and they all work fine except for one. Model RT 1020L plays back just fine but it does not record. It receives the signal but does not record. The relays work. Any ideas on what could be the problem? It also does not erase. I would like to fix it myself. Thanks
E.X.G.
 

bertus

Joined Apr 5, 2008
22,270
Hello,

Are there two heads in the tape recorder?
Of so, one is fed with a high frequency signal to "wipe" the tape, the other is used for recording (normaly the playback head).

Greetings,
Bertus
 

Thread Starter

EXG

Joined Jul 3, 2009
8
I thought of that Dom and you might be right. That would also go for the erase head I suppose. Do you know how to test them? I will try some electronic stores to see who sells tape recorder heads but first I will figure out how to test them. Thanks
E.X.G.
 

Thread Starter

EXG

Joined Jul 3, 2009
8
There are three heads. The erase head, record head and playback head. I believe thats what they are. Thanks Bertus.
E.X.G
 

Thread Starter

EXG

Joined Jul 3, 2009
8
Thanks Sgt Wookie. I am waiting for the manual. Yes it is a fine machine and I am glad you appreciate it. Hopefully the problem is easy to fix. The heads are not worn at all. On top of all that I will have some good reading material that will be very useful. Thanks
E.X.G.
 

SgtWookie

Joined Jul 17, 2007
22,230
As you probably know, they introduced that model in 1973, and ceased production in 1978. That means the components are at least 32 years old. Your prime suspects will be electrolytic capacitors, as these will lose their dielectric as they age. Often, the electrolyte will leak out or simply dry up if the hermetic seal wasn't perfect.

Sometimes they'll blow up and spew their contents on surrounding circuitry. This happens if they've been sitting for a long time and their dielectric strength has weakened; then suddenly power is applied and the high current through the cap causes the electrolyte to boil, creating pressure inside the cap housing.

A good preventative measure is to replace all of the old electrolytic caps with fresh ones from a high-volume distributor, like Mouser, Digikey, Allied, etc.

Sometimes you can re-form old electrolytics, if the electrolyte hasn't leaked or dried out. I just replied to a thread about this yesterday, in this forum. That thread is here: http://forum.allaboutcircuits.com/showthread.php?t=32195

Old resistors are another problem. The old cylindrical brown-body carbon resistors have a tendency to change their resistance over time. I have a bunch of those kinds of resistors that were made in the 70's and early 80's; they were originally 1% tolerance, and many are not even close to what they should be. The newer carbon film type that look like little beige dumbbells seem to hold their values quite well. I have quite a few of these that are 15 or more years old, and are still well within their tolerance.
 

Thread Starter

EXG

Joined Jul 3, 2009
8
Thanks. Always glad to read you responses. I got my first one in 1976 from a friend of mine that bought his while he was in Viet Nam. That one still works just fine and I still use it for various home musical recordings. On this model all the electrolitics look fine as if they were brand new but it does not change the fact that they are old. So now I have a fine repair project ahead of me. By the way the folks at free service manual asked me if I was serious. I said, Yes. I might just have to work on instinct and trial and error. Thanks
E.X.G.
 

VoodooMojo

Joined Nov 28, 2009
505
do the erase heads pull out of the way on playback and then redeploy on record?
could be something in that assembly.
and does that model have playback in the reverse mode?
 

Thread Starter

EXG

Joined Jul 3, 2009
8
The erase head does not move. The tape is moved to it, the record and playback heads. The assembly that does that works fine and makes good contact with the tape. This model does not have reverse play. I do have a model RT 707 that has reverse but there is nothing wrong with that one. Thanks for the suggestion. Every little bit helps.
E.X.G.
 

jbeng

Joined Sep 10, 2006
84
Sounds like the record/erase bias oscillator isn't working. Could be a problem with the oscillator circuit itself or could be a damaged (shorted) erase or record head. Just guesses, mind you...

Jeff
 

VoodooMojo

Joined Nov 28, 2009
505
was it this way when you inherited it or was it working and then just quit?

back in the day, a lot of these decks were used to create a homemade version of an echoplex delay. many times the inputs would give out. I know, I lost a Teac doing this.
I am imagining that when you say the input works you are getting vu meter response?
curious if you were to use this as a preamp and not try to record but use output to an amp if it would have an output?
there is a pre-amp circuit after the vu circuit generally. this gave out from being overdriven. i would love to see the schematic of this machine.
 
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