Analog TX Encoder

[pbunn]

Anyone know of where I can get details on a simple analog encoder. 6 channels or so would be fine.

I am doing a 6 channel conversion on an old Kraft box with no electronics.

I plan to use it on 6 meters.

I think I may have a few NE5044s somewhere but as I remember this chip needed some serious RF bypassing to settle it down. I think I threw away my old Signature 7 board a few years ago.

Pat Bunn

[slipstick]

They don't come much simpler than http://web.telia.com/~u85920178/use/rc-prop.htm

Steve

[Acetronics]

Hi,Pbunn

My old Graupner 6014 Tx has been working for years ( 25 !!! ) with an old NE5044 without any problem ... and no XTRA HF Bypassing.

Buuuuuut see here : http://home.nordnet.fr/~fthobois/TF7N.htm

No special IC needed and it works with classic pots ...

Alain

[pbunn]

I have looked at the simple one using the 4017 - Has anyone tried it? It sure looks simple - I have a PCB about half done using that circuit.

Pat

[coloradoz]

You might want to try the ACERC groups on Yahoo. There are schematics there from all their radios. The silver 7 schematic is what you want. Its 7 channel, expandable - schematics similar to that of that genre, however there are also quite a bit of options that were also available to support mixing - schematics are all there.

[coloradoz]

Better yet, if you want to turn that Kraft into a modern uP controlled radio - look at www.mstar2k.com. There you will find schematics, source code, PCB for a very modern and supported encoder that rivals anything out there today for computer radios. The Kraft is a great platform for conversion because those pots are of the MIL-spec 1M-2M cycle variety.

[pbunn]

Yes - I am building the Msta2K now - I plan to computerize an old Proline radio - single stick

But I want to build a Kraft that is close to vintage looking and the Msta2K is a little too much.

Pat

[coloradoz]

On that microstar (www.mstar2k.com) - there are also schematics for the accompanying RF deck on 6 meters that is fully programmable/setable from the encoder - no more swapping RF decks!

[coloradoz]

Well, If you are interested, I've got a excellent Kraft KPT5C that is fully operational (but needs batteries), on sale right now on ebay.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6028188854&rd=1&sspagename=STRK%3AMESE%3AIT&rd=1

[coloradoz]

I just remembered that I also have schematics for the KPT-7C and 5C encoders. PM me to work out getting copies, if you want to go that route!

[Acetronics]

I have looked at the simple one using the 4017 - Has anyone tried it? It sure looks simple - I have a PCB about half done using that circuit.

Pat

Hi, Pbunn

Have a look to pot value ... not the classical 5k inside Kraft sticks !!! ( I still own a KP4B ... 70's series ...)

Did you noticed The pots values ,slipstick ??? :rolleyes:

Alain

[pbunn]

Yes - I noticed that and don't really want to change the pot value from 5 K.

I seem to remember this same circuit ( the 4017 circuit) from a long time ago and it seems there may have been some minor problems.

Is the NE5044 still available? - I know I have one or two somewhere but findingthem will be a search.

Thanks for the offer on the TX - I actually had several very nice gentlemen here on RC groups give me a couple of transmitters, so I am set there.

Pat

[coloradoz]

According to my factory schematics, the Kraft 76, 77, 78, 79, and 80 series were all 5K pots.

[pbunn]

I think 5 k was pretty much standard - he talks of 500k on the 4017 version.

The Ne5044 is very simple - It would be easy to make a simple PC board - If they are available?

I designed my own 6 meter RF strip quite a while back - but that was in the AM (CW actually) days.

Pat

[Daniel7866]

I have looked at the simple one using the 4017 - Has anyone tried it? It sure looks simple - I have a PCB about half done using that circuit.

Pat

Hi Pat,

This one 4017 based http://homepages.tesco.net/ada.tippett/Radio6.htm worked fine for me. It was part of my first combo UK kit. Maybe hard to get clean dual rate.

Daniel

[ZAGNUT]

Yes - I am building the Msta2K now - I plan to computerize an old Proline radio - single stick

But I want to build a Kraft that is close to vintage looking and the Msta2K is a little too much.

Pat

but then no one is forcing you to use all the microstar's switches, buttons or even the display. would be no problem to have an internal connector you could hook them up to for the occasional programming session...smart inside, dumb looking on the outside :D

but then i do have an NE5044N that's yours if you PM me with a mailing address.



dave

[pbunn]

Daniel,

That one uses 5 k pots and may be the trick.

I was looking at doing something simple with a 16F684 also - I ordered the parts - now to find the time to think out and debug the software.

The 4017 hardware encoder may be an easier path for a simple encoder.

[pbunn]

Zagnut - So many option - So little time.

I will plow through my old stuff and make sure that I don't have one. I may take you up on that offer.

Like usual - I threw away a complete Silver 7 with deluxe sticks a year or so ago.

[FenceMagnet]

The 4017 circuits usually result in a non-linear response.... un-equal throws....

:cool:

[Acetronics]

Hi, Pbunn

We had forgotten the LM 1871 from NS ... if 6 Ch max required !!!

Alain

Hi, Fence Magnet

Non Linear response means your circuit works with a voltage to pulse converter ... not a current to pulse conv. as every good DIYer should have used ...


Alain

[pbunn]

I have just finished a PCB for the 4017 circuit from Britain and plan to test it in a few days.

Incidentally - I requested a quotation for the NE5044 from a IC source on the net.

100 pieces minimum at $9.50 each - These are in Asia.

They found three (3) pieces in the USA and the seller wanted $300 each for the three pieces.

I had forgotton the National part also. I may take a look at the data sheet.

[Reveret]

Hey pbunn
I would have left the encoder circuit if I knew you wanted it. I thought you were going to use a newer encoder and RF deck and would have tossed the Kraft encoder. Send me a few bucks for postage and I will put the encoder in an envelope along with a copy of the schematic and send it to you. I sent the transmitter on Monday and you should get it today or tomorrow.
Bob

[pbunn]

I got the transmitter yesterday and it will be perfect.

I am going to build this Kraft up to look pretty much like vintage - I am building a Mstar encoder - but this transmitter looks so good - I think I am going to leave it cosmetically "Kraft Like"

If you have a Paypal address - PM me and I'll send you the shipping or I'll just drop it a letter.

BTW

I put a circuit board design together and etched it after work tonite fo the British 4017 encoder - built as a 5 channel. Have to get some timing caps and I'll test it this weekend hopefully.

[Reveret]

Good looking board. I'll check but I think the old ACE radios may have used a 4017 base or similar encoder. The NE5044 came a long a bit later and I think I played around with one a bit. If I recall the problem with the ACE encoders was that the the pulse width varied with the battery voltage. Seems like I ended up putting a voltage regulator in one of the ACE radio kits I built to fix the problem.

Check on the box for the shipping cost, I don't remember but seems like it was around $3.75 . Just put it in an envelope when you get a chance.
Bob

[Reveret]

I was wrong, the Kraft 6A uses the 4017 encoder. I'll try to attach the schematic.

[pbunn]

Yes - I have an 8 volt regulator on this board - we'll see how it works

PM me your mailing address.

Pat

[Reveret]

Lets try this again but this time I won't rotate the image.

[pbunn]

Daniel7866

I need an interpreter - The article say "C1 is u15 value" I am assuming .15uF from the looks of the circuit. Is this correct?

Reveret - I put it in photoshop and reversed it already. Thanks again.

Pat

[coloradoz]

Pat, here is a PIC implementation (at great risk of flogging this horse some more), but source code and PCB is included - pretty simple in PICbasic.

http://users.picbasic.org/projects/RcEncoder/radio_control_encoder.htm

..AJ

[Daniel7866]

Daniel7866

I need an interpreter - The article say "C1 is u15 value" I am assuming .15uF from the looks of the circuit. Is this correct?

Reveret - I put it in photoshop and reversed it already. Thanks again.

Pat

Pat,

You are right. For Ts only, C1 is 0.15uF. On my coder this cap was 220nF (7channels) so 150nF would be fine for you.
Nice looking board.

Daniel

[pbunn]

Thanks everyone for the assistance. I hope to test the board soon and see how it works out. I'll let you know.

Pat Bunn