Re: Cannot connect tmd700a with yaac

Doug Alderdice

I wasn't trying to use the Prolific interface with my TMD700, it was in the programming cable for my Wouxon radios.

I have successfully used a USB-RS232 dongle that provides all the control lines with my D700 and the Kenwood software. I don't know who made the dongle, however, I don't see any markings on it.

Sorry I can't be of more help.


Doug, KA2WFT

On 9/24/2020 6:02 PM, Joseph LaFerla wrote:
I am using a “real” com port on my computer.  The kenwood radio requires all pins on the connector because it uses hardware flow control.   I am starting to suspect that my problem has to do with a validation check done by yaac while enabling the port.  What software were you using?
And were you using the D700 or d710?
Sent from Mail <> for Windows 10
*From: *Doug Alderdice <>
*Sent: *September 24, 2020 11:30 AM
*To: * <>
*Subject: *Re: [TMD700A] Cannot connect tmd700a with yaac
I ran into the Prolific problem with an older Wouxon programming cable I
have that apparently has the "wrong" Prolific board in it.  It wasn't a
problem with my older XP system, but it didn't work on my Win7 machine.
Googling told me it was due to counterfeit Prolific boards that some
Chinese m'fr flooded the market with and Prolific was able to update
their drivers such that they could detect a counterfeit board vs. one of
their genuine ones and then refused to let the OS communicate with the
In the case of my Wouxon cable more Googling found me a DIY page whereby
you can a order new USB/RS232 board -- I got it from Amazon -- and
retrofit it into the Wouxon cable and I was back talking to those radios.
I would imagine a similar fix could be done on other cables and
interfaces based on the counterfeit Prolific boards.
Doug, KA2WFT
On 9/24/2020 8:34 AM, David Head wrote:

> Since very few computers have real RS-232 ports any more, I'm assuming

> you're using some kind of USB to RS-232 adapter. If so, here's an

> anomaly I ran into a few weeks ago.


> I have such an adapter, a Trendnet TU-9S if I remember right, which has

> the infamous Prolific chip set that everyone rags on and says doesn't

> work and so forth.   So I attempt to program in TS-2000 after a full

> reset a few weeks ago, and in spite of the setup being exactly the same

> as it was previously, I couldn't communicate with the TS-2000.   I tried

> lots of stuff, including putting a new TU-9s into the system.   Still

> wouldn't work.


> Then I retrieved the cable from RT-systems that came with their

> programming software, put it in the line, and things started working.

> I was able to program the TS-2000 with all the info I had saved


> Why did the old Prolific-based USB to RS-232 adapter stop working?   I

> can only speculate that the bunches of updates that Windows is

> continually receiving somehow messed with the USB communications.   They

> keep updating Win 10, and this and that stop working or work

> differently, it just keeps happening. That might be the problem.


> Dave Head

> K8DH



> At 09:58 AM 9/23/2020, you wrote:

>> I am trying to connect my tmd700a with my aprs client yaac and am

>> getting an error message that the com port cannot open.  I have a

>> straight through rs232 cable connecting the radio to the computer as

>> mentioned in the manual.  I have hardware flow control selected in the

>> com port, the radio and yaac.  I have 9600 selected in both the radio

>> and yaac.  When I try to enable the port, I get a java error saying

>> "Unable to open serial port" .  I have tried everything I can think of

>> to no avail.


>> I have even tried a null modem cable just in case but that does not

>> work.  I am sure I must be missing something obvious.  Any thoughts

>> would be welcome.  Thanks in advance.


>> Joe VA3JLF

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