Schematics for Heathkit GD-47 and GD-19
I obtained the schematics for the GD-19 and the GD-47. Here they are for anybody else who might need them or just use them for reference.
Posted on: 6/26/2012 7:50 AM by Author "crigotti" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=11132337

Heathkit GD-47 and GD-19 Schematics
I'm not sure if this is the right place to post this information, but here goes. I obtained the schematics for the GD-19 and the GD-47. Here they are for anybody else who might need them or just use them for reference.
Posted on: 6/26/2012 7:33 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11132312

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: grotto2 Isn't that industry standard nomenclature? [/quote] LOL! Yeah, I guess it is.
Posted on: 6/22/2012 6:24 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11127560

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: grotto2 [quote]When you referred to a 6 volt regulator, was this a ''3 legged'' regulator or a UBEC? [/quote] Just for the record, I used a 7806 3-terminal. I'm glad your B.A.C. worked, but wonder why the UBEC didn't. Hmmm. On second read, I see you put the UBEC on the RF module. I did it the other way around, regulator on the encoder. [/quote] Ron, That what I kept calling it while I was installing it, a B.A.C.! LOL!
Posted on: 6/21/2012 9:37 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11127323

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 Very good. FYI, I just noticed from your picture that you are using NiMh batteries. If you should have a similar problem in the future, replace the NiMh battery with a NICD or LiFe. The best NICD I have found is the Sanyo N700AAC. It has an ESR of 16 mil ohms. The NiMh I have dealt with, the factory told me they were just below 50 mil ohms. I am new to LiFe, but everything I read indicates a very low ESR. [/quote] Dan, I'll keep the battery info in mind when I go shopping for a new battery. The 2.4 does draw very little current. The battery pictured lasts about 9 hours of continous running. I know, I timed it!
Posted on: 6/21/2012 9:36 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11127320

RE: Logictrol 5 Encoder Pulse Stream
Dan/Ron, I have it fixed. At first I tried using 2 batteries. This worked really well for testing but is impractical. Then I used a 6 volt UBEC I had to power the FrSky board. This did not work, the jitters where still there. Then I tried a big capacitor. I had a 4700uf 35V electrolytic and Bingo! Nice and calm. You can see in the picture how I added the big filter cap. It is held in place using 3M Dual Lock, just like the FrSky board and my summing amp. Now I'm even more pleased with the restoration. Thanks guys once again for all your help.
Posted on: 6/21/2012 5:03 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11127094

RE: Logictrol 5 Encoder Pulse Stream
Ron, When you referred to a 6 volt regulator, was this a "3 legged" regulator or a UBEC? Thanks.
Posted on: 6/21/2012 10:12 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11126690

RE: Logictrol 5 Encoder Pulse Stream
Good idea Ron. Something else to try.
Posted on: 6/20/2012 9:23 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11126081

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 [quote]ORIGINAL: crigotti Thanks everybody for the nice comments. I do have a question though. I have noticed that the servos have a ''jitter'' to them across their entire travel and not just at neutral. If I move them a little bit off neutral, when the servo stops, the jitter is back. Move them full throw, and when the servo stops,the jitter is back
Posted on: 6/20/2012 12:14 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11125484

RE: Logictrol 5 Encoder Pulse Stream
Thanks everybody for the nice comments. I do have a question though. I have noticed that the servos have a "jitter" to them across their entire travel and not just at neutral. If I move them a little bit off neutral, when the servo stops, the jitter is back. Move them full throw, and when the servo stops,the jitter is back. It's not much, but all of them do it and here's a kicker, they seem to do it in unison. I'm suspecting something on the encoder board. I could shotgun the board by replacing all of the componets, but I thought I'd get some feedback from here first. Perhaps the 50 hz oscillator?
Posted on: 6/20/2012 7:20 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11125029

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 You have done a fantastic job on the restroration. [/quote] Thanks Dan. Your help was valuable and much appreciated.
Posted on: 6/16/2012 10:15 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11120829

RE: Logictrol 5 Encoder Pulse Stream
OK guys, I'm finished with "refurbishing" my Logictrol 5. I think it is really a Logictrol III-5. A little history of this transmitter. I got it off a certain auction site for $17. In the pictures it looked awful. It looked like it was in a house fire and all sooty. But for $17, it was worth getting. After I got it, I determined that it was just filthy dirty. No smell of smoke at all. After taking a bunch of pictures, I began taking it apart and cleaning it up. I litterly cleaned every part by hand using Windex and rubbing alcohol. I then cleaned up the stick assemblies and replaced the pots wtih new pots that Kraft used in their radios. I liked them because the pot shaft goes through the rear case, thus providing extra support due to the design of the stick assemblies. I replaced all the wiring with MIL grade teflon wire and wired up the RF meter to display battery voltage. BTW, the meter is now an "expanded scale voltmeter" that goes from 12V to 9V. I then reassembled the transmitter and you know what I had to do to get the transmitter to play with the FrSky RF board. I discovered that I did not need to mount or even have the switch connected to the bind button/LED board for the RF board to work. This RF board also does 2-way telemetry, but for now I'm not using it. I also used an old JR radio charging jack on the bottom. Just before I finished I had an idea to include a digital voltmeter that I got from Hobby King for like a few dollars and I installed it on the inside of the back of the transmitter so it would be visible if I looked into the right stick assembly hole! I can also see the FrSky LED if I tip the transmitter a little. The bind button is easily reached through the same hole. I've included some before/after pictures for you viewing pleasure. Thanks everyone for all your help.
Posted on: 6/16/2012 1:53 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11120362

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: Frank Schwartz I don't know if he has a diagram or not, but I let my old Logictrol 5 and a box full of parts including the receiver and servos to Ron Morgan...never got a thank you note...even though I saw him in Perry GA and he did say something about it...no more goodies for him! Golly, you give somebody something and pay the shipping and they never get back to youi...oh, well.....But he may have a diagram. I have a stack of EK diagrams for the logictrol and Hobby Lobby radios, but that old EK5 is not, I think, in my list of diagrams. Good luck, Frank Schwartz AMA123 86 years young and still building after 76 years and still flying, now that I got my cataracts worked on!! [/quote] Frank, Thanks for the offer on the schematics. But I've traced out the circuits and with the schematics from the latter EK radios, I've figured out what I needed. As a matter of fact, I'm in the middle of completely replacing all the wiring with Mil grade wire. Should be done tomorrow, then I can get back at finishing up the complete restoration of the transmitter. Glad to hear you can see to fly now. All the best, Crist
Posted on: 6/11/2012 9:14 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11115169

RE: Logictrol 5 Encoder Pulse Stream
Here's a layout and schematic of my summing amp. I used some 1/10 inch spacing Veroboard, the strip variety.
Posted on: 6/7/2012 9:05 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11110815

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 Good deal, I feel much better with what you have done. Have fun with your conversion. [/quote] I will and thanks a bunch. I'll post some final pics when it is all done.
Posted on: 6/2/2012 2:28 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11103993

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 JMP and I discussed the situation on Friday. He recommended a stronger pull down resistor from the collector of Q5 to ground. However, that is now a mute point as that is what you have done with the replacement circuit you have done. Your replacement circuit is the right direction as that gets the RF deck out of the picture. Looking at your scope traces, even though it works, I am leary of the down level of the PPM signal. If you plan on using this as is I would check it over a large temperature range, from at least 0 degrees and 150 degrees. However, I still recommend a 2N2222 transistor with a 47K from the base to the collector of Q5. This will present the open collector to the FrSky deck as the RF deck is looking for current flow only on the down level. You can add this to your new circuit easily. [/quote] Dan, I did a temperature range check on my summing amp today. I'm happy to report that it is working from -10 to 210 degrees F. No problems at all. Thanks for all your help. BTW, this has the added resistor and transistor.
Posted on: 6/2/2012 9:56 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11103795

RE: Logictrol 5 Encoder Pulse Stream
Dan, I added the resistor and transistor. I used a 2N4401 transistor. It works. The signal is now "upright" positive shift? The shape is different too. Here are 2 pics of before and after. Both are outputs from the summing amp. Thanks again Dan.
Posted on: 5/30/2012 5:01 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11099146

RE: Cleveland 84
What are you using for the covering?
Posted on: 5/30/2012 10:44 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11100066

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 JMP and I discussed the situation on Friday. He recommended a stronger pull down resistor from the collector of Q5 to ground. However, that is now a mute point as that is what you have done with the replacement circuit you have done. Your replacement circuit is the right direction as that gets the RF deck out of the picture. Looking at your scope traces, even though it works, I am leary of the down level of the PPM signal. If you plan on using this as is I would check it over a large temperature range, from at least 0 degrees and 150 degrees. However, I still recommend a 2N2222 transistor with a 47K from the base to the collector of Q5. This will present the open collector to the FrSky deck as the RF deck is looking for current flow only on the down level. You can add this to your new circuit easily. [/quote] Dan, Thank you for your input. I did plan on checking it over a wide temp range. I don't quite follow your recommendation on using a 2N2222 transistor. I connect a 47K resistor to the collector of Q5 to the base of the 2N2222, the collector of the 2N2222 goes to the FrSky PPM in, and the emitter of the 2N2222 goes to A+ right?
Posted on: 5/29/2012 8:59 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11098564

RE: Logictrol 5 Encoder Pulse Stream
OK, here's the latest. I built a summing amp almost like the one in the schematic and tried it out. It works! The FrSky is driving my servos and all the transmitter functions are normal. I did substitute a 2.4K reisitor instead of the 12K resistor coming off the collector of Q5 to ground and used 2N4403 transistors instead of 2N3638. I'm including some pictures of the summing amp and some of the O'scope waveforms. The first waveform is from the encoder PPM out to the input to the summing amp. The second waveform is the summing amp PPM output to the FrSky board. The last picture is the layout and the parts I used. Let me know what you think. Thanks.
Posted on: 5/26/2012 2:40 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11095454

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 [quote]ORIGINAL: crigotti [quote]ORIGINAL: iflyj3 It looks like the feedback loop for the single shot, diode and capacitor from the collector Q5 to base of Q4, is somehow being affected by the oscillator running. I am stumped without changing out some parts with different values to get the SS working without the xtal. [/quote] Dan, If the RF section isn't transmitting
Posted on: 5/19/2012 8:26 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11086759

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: ScottMcM . [/quote] Scott, I don't understand your post. Please explain the meaning of it. Thank you.
Posted on: 5/19/2012 8:21 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11086750

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 It looks like the feedback loop for the single shot, diode and capacitor from the collector Q5 to base of Q4, is somehow being affected by the oscillator running. I am stumped without changing out some parts with different values to get the SS working without the xtal. [/quote] Dan, If the RF section isn't transmitting, and the FrSky is working, then I'm happy. You are much more versed in this RF stuff than I am. Can I go on and use the transmitter and not worry about spewing RF all over the spectrum and just enjoy the FrSky 2.4 RF link? In other words, do I need to do more to accomplish my goal of disabling the Logictrol RF and enable the FrSky? I do appreciate all the help. I want to do this right.
Posted on: 5/18/2012 9:15 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11086394

RE: Logictrol 5 Encoder Pulse Stream
Dan, Here are some pics of Q5. All have the 2K2 resister installed. The 1st is 1ms no short The 2nd is 1ms shorted The 3rd is 2.5ms no short The 4th is 2.5ms shorted
Posted on: 5/17/2012 7:55 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11085177

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: crigotti [quote]ORIGINAL: iflyj3 Removing L4 stopped the final RF amplifier. The RF is still at the Buffer Q2 which is where the modulation takes place. Since Q2 needs to be working for the single shot to function tells me there is a loading problem for Q5. Did you try the parallel 2K2 resistor that JMP recommended. That should provide enough load for Q5. [/quote] I did try
Posted on: 5/17/2012 4:25 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11084905

RE: Logictrol 5 Encoder Pulse Stream
[quote]ORIGINAL: iflyj3 Removing L4 stopped the final RF amplifier. The RF is still at the Buffer Q2 which is where the modulation takes place. Since Q2 needs to be working for the single shot to function tells me there is a loading problem for Q5. Did you try the parallel 2K2 resistor that JMP recommended. That should provide enough load for Q5. [/quote] I did try the 2K2 resistor, but will try again.
Posted on: 5/17/2012 10:07 AM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11084485

RE: Logictrol 5 Encoder Pulse Stream
[color=#FF0000][size=4]Success![/size][/color] I replaced both Q4 and Q5 with some 2N4126 transistors I had. Still no joy. I could hook up the FrSky to both other Logictrol transmitters (1969 type as in the schematics) and it would work. Now I did not short out the crystal on the other transmitters......hmmm. I removed the short from the crystal and tried it again. No joy. Then I started to probe around a little with the PPM in wire to the FrSky and when I touched the 10K resistor (Collector of Q5), it started working! All 5 channels work great! Now of course I have to figure out how to disable the 72mhz transmitter section without shorting out the crystal. One thing I noticed, with the crystal shorted, there was no faint buzzing sound from the board. With the short removed, the buzzing sound came back. BTW, when it was all working and with power applied, I shorted out the crystal and the FrSky stopped working, remove the short, its working. Enclosed is a picture of where I tapped off for the PPM stream to the FrSky. Any ideas on how to disable the RF section?
Posted on: 5/16/2012 9:23 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11083763

RE: Logictrol 5 Encoder Pulse Stream
I looked at the schematics again and decided I could disable the RF section by removing L4. I did and the FrSky still works. How can I check to see it the RF section is really disabled?
Posted on: 5/16/2012 8:56 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11083899

RE: Logictrol 5 Encoder Pulse Stream
Dan, Yeah, I probably replace both them tonight. In the meantime, I gathering a parts list for the encoder board just in case I decide to replace the componets. I have everything figured out except the 2 "polyester"? caps in the picture. These are the ones wth the color bands on them. I have come up with a value of .15uf 10% 250v. Did I figure that right? Can these be substituted with a ceramic disc cap? Thanks for all the help so far. I really appreciate it.
Posted on: 5/16/2012 12:07 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11083231

RE: Logictrol 5 Encoder Pulse Stream
I got out my 1969 27mhz Logictrol and the FrSky worked great when hooked up to the anode of the diode or the collector of Q5. here is 2 pictures of the RF board showing where I hooked up the FrSky unit.
Posted on: 5/15/2012 9:13 PM by Author "crigotti" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11082503