Build your own Flash Cable

Hi, and thanks for the awesome forum! And yea, I got a very good price for the 620’s, and figured “why not?” - they are for the Latin America market, and MAY be different frequency hops, but I have never been able to determine for certain if they really are different, or if it is the same transciever and chip, just using different keys. In which case, they SHOULD be able to be reflashed as a different model, and we are off to the races.

More likely, based on what Moto advertising I can find, is that these are 1st gen, and may not be able to be retrained. But their later ads all show 620 and 410 playing nice with each other, and in other adverts showing 410 and 550/650 playing nice. So there very well could be a connection, they just didnt want to have two identical models in the NA market.

Of course, I could just be blowing smoke. Only one way to find out, but I was hoping to get a flash cable for less than the $120 I am finding online. I only paid $80 for the two radios…

Good Info. Thanks.

For those that were wondering, the NKN6559A cable works perfectly for building your own cable. The Radio end fits properly and opening it up to rewire it isn’t too difficult if you’re handy with electronics.

I just have to figure out what to mount the DC-DC converter into as a decent-looking lump in the middle of the cable…

Flash Cable 1 DC-DC & Connector

Cool! I’ll have to get the NKN6559A cable on order and give it a try.

A small project box completely covered with heat shrink tubing for the dc-dc inverter might look OK.

Exactly what I was looking for. Thank you!

I finally got around to building a flash cable. Now all my radios are upgraded and are programmable through the CPS! Here’s a photo of the completed cable:

Bruce Flash Cable


Nice job! Looks much better than the mess I ended up with! :wink:

I was fortunate in being in the same country as Andy and being in similar industries, so he was nice enough to lend me his programming cable for a week. (I only had to upgrade five radios.) I am wondering if it is possible for anyone who has the factory cable or has built their own, to post where they are from and if they are willing to loan or rent their cable out to others on this forum. Because this cable is likely to be used only once, it seems silly to throw it in a drawer for the rest of time when so many other users could gain an advantage by borrowing it for a week. Obviously people would need to trust each other for this to work, but I was lucky in that Andy was not only very knowledgeable and professional, he was a very nice guy too. (Sadly, I think he already sold his factory cable, darn it. I would have bought it just so I could lend to others!)

Good idea. I’m willing to let people use my home built cable if they bring their radios to my location. I’m located in Mississauga, Ontario.

Here’s a schematic for the home made flash cable using a donor NKN6559A cable and a DC-DC inverter. I found that the switch is not really necessary, just connect the positive input of the inverter directly to the +5VDC line.

DTR flash cable construction.pdf (51.0 KB)

Yup! That’s what I did too, just not as nicely packaged. What was the intention of the switch originally?

In some photos of the original NNTN6367A flash cable there is a flash switch. I guessed that it turned the +12VDC on or off and decided to replicate that funtionality to see what it did.

It turns out that connecting to the DTR radio when the +12VDC line is off allows it to show up as iden modem to the PC. However, there doesn’t seem to be anything useful about that so the switch is not required.

10-4. I had a few of the “real” flash cables. I had thought (in my hopefulness) that switching the switch the other way would turn it into a CPS cable. No such luck. No idea how the other mode would be useful.
It would be interesting to make an adapter that was dual-purpose that way. I have a bunch of USB->RS232 circuitboards… hmmm… :eusa_think:

Hello does anyone have unbroken link to buy usb programming cable for dtr650 …

You mean a flashing cable? If you’re looking for a programming cable, there are still those around on eBay and other places.
If you’re looking for a flash cable, how much would you be willing to pay?

I’d be willing to buy one if you had one available.

Well, I had 2; sold them on eBay. The last one sold for $200.00. I don’t think people will be willing to pay that much anymore.


Following the instructions in this thread, I successfully built a flash cable and flashed one of my old DTRs up to the current firmware version!

A few things I learned along the way:

  1. After cutting the USB cable, I used the shield to carry the +12V from the DC-DC converter. At the Motorola plug end, the shield was soldered to the metal retention clip on the plug. Make sure you remove this and connect the +12V only to pin 15. I believe the retention clips contact the grounded shield around the receptacle on the radio, and this would cause a short.

  2. The R5E.06.01 update utility ran properly on my Win7 x64 laptop following the included instructions, but I had trouble running the R5E.06.05 utility. When I opened the DTR flash program, there were two lines below the flash button, USB and COM. If I tried to flash I would receive an error: “Error> Reverse flash is not available when multiple devices are connected”. The solution was to edit the DTR Flash.cfg file in the program directory, and change the first line from “comm_protocol=0” to “comm_protocol=1”. After that, the program would run with only a single USB entry, and the flash proceeded without error.

Thanks again for all of the info! I couldn’t have done it without this great site.

Glad to hear it! I keep meaning to put together some more flash cables and perhaps offer them here or on eBay. I have all the parts, just not the free time…

paid $25 to get a CPS cable. it works. now I need to build a flash cable. only cable that is available is on Ebay for $185. I have all the tools except a cheap DTR connector that I can solder wires onto. I searched Ebay and none (NKN6559A, NNTN4049A, etc) is available under $10. Anyone could point me to a cheap wire with DTR connector?