[Kenwood] Re: TH-F6A @ 9600 baud?

[Andrew Langenderfer]

I almost forgot- With the HT at rest (not transmitting) I can measure a sustained 4volts DC on the HT data input (middle conductor of the 3.5mm plug).  Is this condition supposed to exist?

Thanks again,
Andrew

---------- Original Message ----------------------------------
From: "Andrew Langenderfer" <lang49 at fsuimail.ferris.edu>
Reply-To: <lang49 at fsuimail.ferris.edu>
Date:  Tue, 22 Feb 2005 12:32:47 -0500

>Hello Everyone,
>
>I'm wondering if anyone has actually been successful in using a TH-F6A at 9600baud.  I am attempting to couple the TH-F6A with a Kantronics 9612+ and am having no success.  Regardless of how hard I drive the radio with the TNC, I don't seem to get any real modulation.  
>
>Without the TNC plugged into the Mic input of the radio, I can view the output from the TNC with an O-scope.  Using the drive adjustments of the TNC (XMITLVL) I am able to varying the output from a couple hundred mV p-p to approximately 4 volts p-p. 
>
>Once the TNC is actually attached to the radio, I cannot get more than about 200mV p-p output from the TNC.  Regardless of how I change the transmit level coming from the TNC, the voltage at the data output pin remains low- as if the HT is dragging it down.
>
>At the advice of Ken in the Kantronics tech support department, I have put a 10uF capacitor in series with the data output line of the TNC, and the middle conductor of the 3.5mm plug (mic input).  However, voltage between the capacitor and radio is still drastically lower than the voltage leaving the TNC.
>
>Ultimately i have to wonder- do I have defective radio, or is there something special I need to do in order to couple the TNC and radio?  Incidently, this HT/TNC combination works flawlessly at 1200 baud.  As well, I actually own two brand new 9612- the same problem is present regardless of which TNC I connect to the HT.
>
>Thnaks in advance,
>Andrew KC8LQY
>