Wanted Kraft schematics

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ShowMaster
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Re: Wanted Kraft schematics

Post by ShowMaster » Mon Jun 18, 2012 5:21 pm

Rob
Did a 'Retro Transmitter Mods' topic ever get started?
I have my Kraft pictures I can post.
SM

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Wanted Kraft schematics

Post by Rob Thomson » Mon Jun 18, 2012 5:31 pm

Yes! This thread has already been moved in to it :)


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Re: Wanted Kraft schematics

Post by ShowMaster » Mon Jun 18, 2012 5:45 pm

Ok I see it now, missed it.
SM :oops:

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Re: Wanted Kraft schematics

Post by ShowMaster » Mon Jun 18, 2012 6:29 pm

Here are some pictures of my Frsky modified series 79 TX. Its flown 5 great flights but I need to recenter the encoder to 1.5Ms instead of 1.4 if I want to intermix it with my flying planes using er9x. I'm not sure if that will work out but I'll know more when I try it. My nice scope given to ,e has developed many issues so it may be more trouble to fix it than I want to spend on it for now. I have a backup but I'm thinking of buying a software defined one for $200 or less I see others using here. I could use some good current recommendations on one and any software issues I can "patch".
Now that I've found a good Kraft encoder schematic for my series I'm able to see what's going on and what adjustment options I have, whew!

The Frsky DHT "Toggle" I don't use much or at all so it's just hot glued where I can get to it if needed. I can move it if I do ever use it a lot. I can't find a source for the 6 pin din male Kraft used so I'll be opening up the TX to charge the LiFe but that may be the safe way to go anyway. I'll deal with the plug issue later.
My next challenge is a 5 Ch series 1978 that has a much smaller battery box so I may have to remount the encoder board to allow for a LiFe batter install. I don't plan to use any other type batteries at this time. The series 78 will take a standard 8 cell stick pack as well after the battery box cutout mod.
I have a Kraft single stick I modded a while back but it's fussy about battery voltage lately so I'm going to have to "bench it" and see what's going on.
This and modding 9x radios for friends and my sky9x as well as flying has kept me busy. Not as busy as MikeB and others it seems when I read the posts. I don't write code so I keep busy while they do helping others and giving life to otherwise trashed radios from the past. It's a lot of fun when it all works and I'm sure I'm not alone here or this site would not exist.
SM
Attachments
LiFe Install Bat Box.jpg
LiFe and modified Bat Box. Perfect Fit
Bind install in TX Module2.jpg
Final Look
Bind install in TX Module bottom.jpg
Bind installed Module bottom
Bind install in TX Module1.jpg
Bind installed in TX Module
DHT & 1500Ma Life.jpg
DHT & 1500Ma LiFe Mods installed

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Re: Wanted Kraft schematics

Post by flybabo » Mon Jun 18, 2012 8:31 pm

SM,
Could you PM me your surface mail address?
I have a surprise for you.
HT


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Re: Wanted Kraft schematics

Post by ShowMaster » Tue Jun 19, 2012 2:32 am

flybabo wrote:SM,
Could you PM me your surface mail address?
I have a surprise for you.
HT
Oops I sent you my email address. I'll send another pm.
The email is good for any links in any case.
Thanks
SM

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Re: Wanted Kraft schematics

Post by nickhawk » Thu Dec 20, 2012 5:41 pm

Hello Guys , I have several kraft radios from the seventies but my attention is a series 72 single stick. Anyone who does know where is the ppm signal? Unfortunately I do not posess an oscilloscope.Also an interesting mod would be the old good brown Futaba radio from the seventies....

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Re: Wanted Kraft schematics

Post by ShowMaster » Fri Dec 21, 2012 7:59 am

You may be in luck on the Kraft.
I a single stick and a few two stick ones of that era. It's a little busy with the holidays but I'm sure I can help you.
We may have to exchange encoder board pictures to make sure of the wiring color codes.
As for the Futaba, easy if you had a scope but may require some creative circuit tracing without one.
I'm assuming you're going to use the Frsky DHT DIY 2.4G solder in module?

Something to look Into, there are free PC scope programs that use the audio input port. You make a probe from an audio cable and a simple resistor divider circuit.
The ppm data is slow enough that the program and a PC can display it.
Not sure about a Mac program.

SM


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Re: Wanted Kraft schematics

Post by nickhawk » Fri Dec 21, 2012 12:34 pm

Hello Showmaster,
Thanks for your reply my electronic knowledge is very basic though my transmitter collection is large...My sentimental connection to retro radios of the 70ies is very strong.It was the time I could admire the wonders in the various magazines but not buy them...I see in all the forums with old Tx modifications that there are many succesfull attempts with different radios but the information given to the public afterwards is very limited for people like me who work mostly with photos than electronic schematics.
I used the frsky set in a couple of radios but I prefer the jeti duplex system and the multiplex m-link which are alot more expensive than the frsky but more reliable. I did download the pc programm of the scope but as I said I cannot use it yet due to the lack of knowledge.I will post just for the records some of the mods I did in TXs with detailed pics and info.

Regards and Merry Xmas to all
Nick

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Re: Wanted Kraft schematics

Post by ShowMaster » Fri Dec 21, 2012 3:09 pm

Good to know about your radio restoration projects.
For the most part I should be able to help. A few pictures of the TXs and series and I may be able to send you the schematics.
I'm not sure if they can be openly posted in the forum so we can chat via email when it's time to do the mods.
First is deciding what series of Kraft encoders you have. Are any module type or all dedicated rf outputs?

Dealing with the pulse trains and levels is much easier however with a scope.
Being good sigh a meter, scope, and schematic reading will really enhance your restoration projects and mods circuit interface quality.
May I suggest that you try a few of these scope programs and if we both use the same one it can be used as a reference data exchange.
This may also get others on board using them to help with operating tips

The basic principal I'd the program uses the input to your sound card and displays a screen graph/display of voltage vertically and pulse with horizontally. You construct a probe from posted plans and you're good to go.
I've not bothered personally to use a PC program because I bought a cheap scope at a ham radio swapmeet some time ago.
I'm willing to try a few programs however since many are scope less on the forum.

My final reasoning for a scope option is that sometimes the data levels may work but a scope shows them on the ragged edge of working, or distorted, ect.
It can mean the difference between a solid system or one that never seems quite solid or worse, does wierd things.

Good New Years resolution, improve on your test equipment options and learn how to use a scope.

Ok, get that radio list posted and let's see what progress can be made.
SM




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Re: Wanted Kraft schematics

Post by nickhawk » Fri Dec 21, 2012 4:28 pm

[img]C:\Documents%20and%20Settings\nikos\My%20Documents\My%20Pictures[/img]

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Re: Wanted Kraft schematics

Post by nickhawk » Fri Dec 21, 2012 4:39 pm

Ok I did send you my e-mail address as soon as I get yours I will mail some pics of the PCB s and I will also download the scope programms you mention. I tried to upload a picture of a part of my collection of radios but it seems the programm won't let me upload one from my files.I am I wrong?

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Re: Wanted Kraft schematics...the memories..

Post by mosfetman » Tue Feb 05, 2013 5:07 am

Just this morning I was thinking about retrofitting a 9X type board into one of my retro radios. The Microstar2000 guys have built some beautiful pieces with the Microstar encoder. I own about 100 retro radios and I have sold over half of my original collection! I never got my hands on a Signature Series although I own several nice Z series radios on 6 meter ham band.

BTW...I still fly 1973 ProLine AM Wideband receivers on ham band and I have never lost a plane with them. I use the Microstar synthesized 6 meter RF deck. It handles 50/53, AM/FM, channels select-able via the Microstar encoder or with binary rotary switches.

Also, Gordon Anderson, the creator of the Microstar is reported to be working on FW for his encoder that will support the FrSky DIY 2.4ghz module.

If you are restoring a vintage radio, I have parts available...PM me..
JP
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Re: Wanted Kraft schematics

Post by StampeSV4c » Sat Feb 09, 2013 8:14 pm

I just ordered a Frsky DHT DIY unit. I have a Kraft series 78'/5C & 71'/7C Single stick plus a 70'8chSS Heathkit. I have been reading several blog sites on this conversion subject. However, there seems to be a varying degree as to whether or not the PPM needs to be stabilized at 5v or the polarity be inverted on the Kraft unit. Either way I am excited about converting my radios over to 2.4Ghz but I would like to know if the Frsky unit will work 'out of the box' and connected to the PPM 'line out' without the additional diodes etc... on the Kraft.

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Re: Wanted Kraft schematics

Post by ShowMaster » Sun Feb 10, 2013 5:48 am

The Frsky module has a Schottky diode in line with its ppm line now for over a year, maybe more now to protect it. If your DHT DIY is newer and has the toggle switch yours has the mod. The CPU has its own pull-up resistor and can take any polarity ppm in.
The DHT also has its own 5v regulator so it can run with tx voltage.
SM



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Re: Wanted Kraft schematics

Post by mogplus8 » Wed Feb 13, 2013 12:22 pm

Hi Guys,

Just discovered this forum and this thread. Very happy indeed as I have been trying to find out about converting my old Kraft FP-T8SSAP single stick to 2.4 Meg since I got it a couple of months ago. All the advice I've been given is that it can't be done as it's PCM. So I spent a lot of time (and money) getting a 36 Meg module and receiver that would work with it as the original was 72 Meg (not legal in Oz). After many dead ends (and more money...) I obtained a transmitter module, and learned that the only receivers that will work with it are the R118DP (discontinued in 1994) and the R128DP (discontinued in 1998). I finally got a 36 Meg R118DP, plugged it in and it all worked! But I would still love to convert it to 2.4 if possible. My electronic knowledge is basically nil, but I can solder wire A to point B successfully if I've got very clear instructions! So if there is a PPM signal in there somewhere I think I've got a sporting chance of getting it to work.

All advice gratefully received!

;) Ian

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Re: Wanted Kraft schematics

Post by ShowMaster » Wed Feb 13, 2013 4:14 pm

Wow, I didn't know Kraft made a PCM system.
I have many old schematics and I may have a encoder p e for that time frame. May take a few days to find it.
In the meantime,
Does it have a trainer port and switch option? Many times that may be a ppm in and out port.
A would like to see some pictures of the front and any connectors and switch labels.
Any links you have to this system would be nice.
With out a scope it's a little difficult. Not having the myself makes it hard to suggest wiring changes. Maybe whole this is up in the air so to speak, you can ask around your friends, RC club members, ham radio operators, if they own a scope.
They don't have to be RC flyers to help you if they have the equipment and know how to use it.
SM


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Re: Wanted Kraft schematics

Post by mogplus8 » Thu Feb 14, 2013 2:19 pm

Hi SM,

I'm an idiot. Not Kraft. Futaba. It does have a trainer port, a six pin din plug. I thought there might be a PPM signal there but I've got no way of knowing. Have to explore the PC/oscillascope thingy you mentioned in some of your other posts.

Found this link a while back http://www.rcuniverse.com/forum/m_11157 ... m#11161855 where a guy converted a Futaba SS to 2.4 by using the PCM to PPM converter in a receiver, then connecting that up to a 2.4Gig module. He's now selling it on Ebay http://www.ebay.com/itm/Vintage-Futaba- ... 0260090%26

;-) Ian

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Re: Wanted Kraft schematics

Post by ShowMaster » Thu Feb 14, 2013 11:23 pm

Ok, now it makes sense! I should have know by the model # you posted.
Wow, a lot of work but worth it of you want a vintage Futaba SS.
I can't be of much help I'm afraid. He seems very knowledgable and technical and of he couldn't find a ppm signal in the tx without his extensive mod then your going to have to duplicate his work.one thing not mentioned is the latency/lag introduced by all the conversions?
It's a shame Futaba doomed this system by making it PCM only. But that was going to be the answer to everything furring that time frame. I lost several planes to my pcm10 going into failsafe and not returning fast enough and luckily was able to switch to FM PPM. I still fly it with a Frsky DJT module and ppm. I have a PCM 9 that will never fly again because its hard coded PCM and the RX's are a brick. It's part of my collection collecting dust.
SM
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Re: Wanted Kraft schematics

Post by mogplus8 » Sat Feb 16, 2013 9:01 am

I guess the easy option is to rip the guts out of it and replace it with a 9x board. Seriously considering exactly that. It would be nice to keep it all original and all (especially as one the same but complete with servos and receiver etc, recently sold on Ebay for over two grand!) but I bought it to fly with. The stick has a fantastic feel to it, very positive. I have a JR Century 7 single stick too, and the stick springs are much softer. (but it is PPM. I plugged in an FrSky module and it worked first time). Feels a bit wishy-washy after using the Futaba. I've also got an old Kraft three axis stick (from my old Heathkit set from decades ago) and another one I bought from a robot hobbyist shop. None of them are as nice as the Futaba.

Speaking of my JR, the module nearly fits but not quite. I've read that some people have ground away the plastic on the module to make it fit. Tried that on mine (think I may have, ahem, ground away a bit of the circuit board too...) but it still wouldn't seat properly. Also tried trimming the pins sticking out of the back of the tranny to see if that was the problem. It wasn't. The seat was better, but still a mm or two out. Do you know how to remove the circuit board from the back of a FrSky DJT module? I tried but it appears to be glued down. I couldn't budge it. (hence the attempt to modify the case with the circuit board still in place...) I'm thinking if I can remove the circuit board I could grind away a bit more of the case (safely) then reinstall the board, maybe with a couple of spacers or a bit of foam or something so it was about 2mm higher in the case, then it might fit. (I've got another undamaged one).

Another question. How easy is it to reroute the aerial lead to an aerial mounted on the case? Is there any issues with doing this? (other than making it difficult to change modules.) I've got the original 72Meg module which is flat. I'd like to put the 2.4 board into it and then route the aerial wire to an aerial mounted where the existing telescopic aerial is.

Apologies if I'm a bit off topic with this one, should I start a new thread? Especially as it's not even really 9x related... But a few posts have talked about restoring vintage radios, and it fits pretty well into that mold. And I'm considering replacing the Futaba's innards with a sky9x module.

Thanks,
Ian

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Re: Wanted Kraft schematics

Post by StampeSV4c » Mon Feb 18, 2013 4:17 am

OK,now that my questions about the Frsky module installation in my Kraft,(thank you ShowMaster), I would like to know some thoughts about adding the OrangeRX DSMX/DSM2 module to the up-graded Kraft. My thoughts would be to remove the OrangeRX module from it's case and use a common 2.4 antenna for both the Frsky and the OrangeRX. Perhaps adding a toggle switch to select between the two modules and installing the bind button on top of the TX. The Futaba radio has 5 pins for the module base and I surmise that a Futaba schematic would provide the info about the pin input/output.

From what I have read about the OrangeRX, this additional module would allow using the Kraft with the Bind and fly.

Also, I found a link for schematics on the Heathkit 8chss http://www.vintage-radio.info/heathkit/

Thanks,StampeSV4c

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Re: Wanted Kraft SS info

Post by NineYards » Mon May 19, 2014 9:40 pm

Would like to have people that have converted their old Kraft Single Sticks to 2.4ghz. I need info from anyone that has done this and how it is working out for them.

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Re: Wanted Kraft schematics

Post by ShowMaster » Tue May 20, 2014 4:29 am

I modified mine early on, flew it ok. I did have some issue with it several weeks later. It acted like the frsky RX was getting interfered with. I had many projects going so I put it on the shelf and never got back to it.
Maybe it's time to find time again.
ImageUploadedByTapatalk1400559174.877117.jpg
ImageUploadedByTapatalk1400559228.762691.jpg
I've been able to gather what I think are all the Kraft schematics on the different years models.

Kraft didn't use any regulators for the logic and I'm thinking I may add one to stabilize the buss.

I also modified a dual stick Kraft.
ImageUploadedByTapatalk1400559687.760675.jpg
ImageUploadedByTapatalk1400559785.643307.jpg
While I'm at it, I'm sorry I didn't reply to the one antenna for Frsky or the orange DSM module and an antenna toggle switch.

NOT a good idea! RF being AC, not DC, travels through capacitance. Switch the toggle from one to the other module will not disconnect the modules from the RF passing into each other and causing damage or RF loading, or worse.

If I can help with some Kraft schematics we should pin down the model board you have.
I may have some Heathkit tx info if I look.



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Re: Wanted Kraft schematics

Post by deaconFlyer » Wed May 21, 2014 9:55 am

Fascinating thread. I have a 7CS (Series 79) that has been modified to work with an XtremeLink module.

Rock solid performance and a lovely throw-back feeling.

I will try to get some pictures of the internals of the mod. It would be nice to see some from any mods others have done.

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Re: Wanted Kraft schematics

Post by ShowMaster » Wed May 21, 2014 2:37 pm

After flying my Taranis for a year my Kraft sure is a challenge. No display, multiple memories, sub trims, box is heavy. It's a wonder we flew a plane with it ha ha.

Yes I'd like to see your install. Many opinions about the tx module choice but getting a solid ppm signal to it and mounting the LEDs and any bind button is what I'm looking at.
I like to keep it a clean look.

What I'm really interested in is discussing the ppm centering calibration and power rail regulation.
Kraft for many versions didn't use any regulation I see. I believe even the versions that used a few ic's didn't.
My thinking is to not have the encoder run on the tx pack directly.
I tried to keep the circuitry stick but I'm retching it for stability.
Kraft used 1.4Ms as ppm center as I remember. I'm thinking of changing the timing to 1.5 to match the current standard.

I use the Frsky DHT DIY tx module because it and the D series receivers have telemetry, and I can monitor my RX pack if used, and my lipo pack for my electrics. I'm spoiled now.

Ideas
This could be a fun topic to get active. I think we should post our radio models with pictures, and our mods done.
Any schematic info to share or wanted.
I have gathered many radio schematics. We may want to set up an email to share them on a need to know basis, as I'm not sure if we should post them for legal reasons?

I only wish I'd kept my Proline radio.




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Re: Wanted Kraft schematics

Post by drmolina » Sun Nov 16, 2014 11:48 pm

I have a dual stick series 77 and series 78.... I haven't been able to find the ppm signal to do a frsky hack.... can someone send me some pictures of where the wires are located.... I guess that this has to be by the module or trainer port pins.....

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Re: Wanted Kraft schematics

Post by ShowMaster » Mon Nov 17, 2014 2:49 pm

drmolina wrote:I have a dual stick series 77 and series 78.... I haven't been able to find the ppm signal to do a frsky hack.... can someone send me some pictures of where the wires are located.... I guess that this has to be by the module or trainer port pins.....
Yes it will be one of the module pins and also on the trainer port. A scope really helps there. That or scope program.
A picture of the case front, top and back would be nice for reference. Does this model have the plastic frequency modules? I mounted my DHT buttons in mine to keep the stock look.
Where are you located? I may be able to help you with a diagram but I'm not sure about the wire colors of the ppm signal.
SM

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Re: Wanted Kraft schematics

Post by drmolina » Wed Nov 19, 2014 3:20 pm

I'm in NJ..07450

They do have the plastic freq modules.... I've done over 15 conversions but none on the Kraft... I thought the World Expert radios would be difficult but they do have the ppm chip so they were rather simple..... The Krafts don't use that chip and they are a remarkable electronic wonders but the PPM signal is somewhat ambiguous...

Send me a pm and we can exchange emails... Maybe I can send you the TX's for you to mod them...

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Re: Wanted Kraft schematics

Post by ShowMaster » Thu Nov 20, 2014 4:33 am

Sorry, no time to do extra mods. Having a scope or scope program is a great help in tracing the ppm signal wire.
I'm tied up until the weekend but I'll look up the schematics for the year/series Kraft I think you have for wiring. I'm not sure colors are listed on the schematics. Basically, the module has ground, 9.6v battery, tx antenna out, ppm in from the encoder and tx out kill if it has a buddy box option.
I believe you could use a free scope computer pgm and a DIY probe for the audio in port. Just using an audio amp/computer audio input would let you hear the ppm growl that changes with stick movement. You must add a series cap (.1ufd ?)to block DC and a maybe 1k resistor into the probe. Usually the scope programs have probe design info.
SM

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Re: Wanted Kraft schematics

Post by pjf610 » Mon Feb 29, 2016 4:21 pm

Hi ShowMaster i am new to this forum i have bin looking for Kraft Schematics and i got this site my question to you is did you come across the Kraft Manuals on CD and if so were can i get them from??

Pat

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