Adjusting Kenwood D700 Internal TNC for 9600 Baud


Scott MacGillivray, KM6RTE
 

Greetings,

 

I recently set up a new dual band (VHF & UHF) Winlink RMS Packet gateway.  The UHF band uses a Kenwood D700 radio that is set to operate at 9600 baud.  A nice feature of this radio is that it has an internal TNC, which made the set up very easy.  I was able to fully check-out the system from my shop (utilizing short distance “test range”) and it operated fine, without any issues.  However, when it was installed at its final location (assessable to a large number of stations), I got reports from stations that they weren’t able to connect or have a successful session with it. 

 

In my limited research into this issue, I’ve found that operating at 9600 baud frequently requires that the TNC be “fine-tuned” (my words) to support this faster speed.  Other operators have informed me that I need to tweak the radio’s “deviation” (?).  I have access to an older model IFR FM/AM-1000S Communications Service Monitor (with unknown calibration) in order to evaluate the radio’s TNC performance. 

 

Can anyone provide me with any good resources or information on 1) how to setup the Service Monitor, 2) what performance parameters I need to be looking for, and 3) what are the TNC settings (and recommended values) for the D700 that need to be changed in order to optimize its performance?  I don’t have a strong RF/electronics background, so I suspect I need this explained simply. 

 

Thanks in advance for any assistance you can provide. 

 

Scott MacGillivray, KM6RTE

Orange, CA

 


qp2trz
 

The D700 has a service mode you can access with the right set of launch codes.
Google is your friend. 73

Joey
VA3GOC VE3XMU


John Huggins
 

Not quite sure about the 700, but I suspect the deviation settings for it and the later 710 models are already optimized, deviation and sensitivity wise, quite well for 1200 and 9600.  These Kenwood's are well known for better 9600 than 1200 although both work out of the box.

Being optimized for APRS UI AX.25 use, the internal TNC may not have sufficient buffering for AX.25 connected mode.  Many folks who do use the 700/710s for connected mode do it with an external TNC that usually have no problem with any AX.25 mode of operation.

John, kx4o


On Sat, Oct 9, 2021 at 5:39 PM Scott MacGillivray, KM6RTE <csmacg45@...> wrote:

Greetings,

 

I recently set up a new dual band (VHF & UHF) Winlink RMS Packet gateway.  The UHF band uses a Kenwood D700 radio that is set to operate at 9600 baud.  A nice feature of this radio is that it has an internal TNC, which made the set up very easy.  I was able to fully check-out the system from my shop (utilizing short distance “test range”) and it operated fine, without any issues.  However, when it was installed at its final location (assessable to a large number of stations), I got reports from stations that they weren’t able to connect or have a successful session with it. 

 

In my limited research into this issue, I’ve found that operating at 9600 baud frequently requires that the TNC be “fine-tuned” (my words) to support this faster speed.  Other operators have informed me that I need to tweak the radio’s “deviation” (?).  I have access to an older model IFR FM/AM-1000S Communications Service Monitor (with unknown calibration) in order to evaluate the radio’s TNC performance. 

 

Can anyone provide me with any good resources or information on 1) how to setup the Service Monitor, 2) what performance parameters I need to be looking for, and 3) what are the TNC settings (and recommended values) for the D700 that need to be changed in order to optimize its performance?  I don’t have a strong RF/electronics background, so I suspect I need this explained simply. 

 

Thanks in advance for any assistance you can provide. 

 

Scott MacGillivray, KM6RTE

Orange, CA

 


John Huggins
 

Let me add a resource from the wayback machine that may help...


On Sat, Oct 9, 2021 at 6:35 PM John Huggins <john.huggins.ee@...> wrote:
Not quite sure about the 700, but I suspect the deviation settings for it and the later 710 models are already optimized, deviation and sensitivity wise, quite well for 1200 and 9600.  These Kenwood's are well known for better 9600 than 1200 although both work out of the box.

Being optimized for APRS UI AX.25 use, the internal TNC may not have sufficient buffering for AX.25 connected mode.  Many folks who do use the 700/710s for connected mode do it with an external TNC that usually have no problem with any AX.25 mode of operation.

John, kx4o

On Sat, Oct 9, 2021 at 5:39 PM Scott MacGillivray, KM6RTE <csmacg45@...> wrote:

Greetings,

 

I recently set up a new dual band (VHF & UHF) Winlink RMS Packet gateway.  The UHF band uses a Kenwood D700 radio that is set to operate at 9600 baud.  A nice feature of this radio is that it has an internal TNC, which made the set up very easy.  I was able to fully check-out the system from my shop (utilizing short distance “test range”) and it operated fine, without any issues.  However, when it was installed at its final location (assessable to a large number of stations), I got reports from stations that they weren’t able to connect or have a successful session with it. 

 

In my limited research into this issue, I’ve found that operating at 9600 baud frequently requires that the TNC be “fine-tuned” (my words) to support this faster speed.  Other operators have informed me that I need to tweak the radio’s “deviation” (?).  I have access to an older model IFR FM/AM-1000S Communications Service Monitor (with unknown calibration) in order to evaluate the radio’s TNC performance. 

 

Can anyone provide me with any good resources or information on 1) how to setup the Service Monitor, 2) what performance parameters I need to be looking for, and 3) what are the TNC settings (and recommended values) for the D700 that need to be changed in order to optimize its performance?  I don’t have a strong RF/electronics background, so I suspect I need this explained simply. 

 

Thanks in advance for any assistance you can provide. 

 

Scott MacGillivray, KM6RTE

Orange, CA

 


David Ranch
 


Nice link John.. thanks for that little nugget.  Too bad it's gone off the primary website though.

--David
KI6ZHD


On 10/09/2021 05:44 PM, John Huggins wrote:
Let me add a resource from the wayback machine that may help...


On Sat, Oct 9, 2021 at 6:35 PM John Huggins <john.huggins.ee@...> wrote:
Not quite sure about the 700, but I suspect the deviation settings for it and the later 710 models are already optimized, deviation and sensitivity wise, quite well for 1200 and 9600.  These Kenwood's are well known for better 9600 than 1200 although both work out of the box.

Being optimized for APRS UI AX.25 use, the internal TNC may not have sufficient buffering for AX.25 connected mode.  Many folks who do use the 700/710s for connected mode do it with an external TNC that usually have no problem with any AX.25 mode of operation.

John, kx4o

On Sat, Oct 9, 2021 at 5:39 PM Scott MacGillivray, KM6RTE <csmacg45@...> wrote:

Greetings,

 

I recently set up a new dual band (VHF & UHF) Winlink RMS Packet gateway.  The UHF band uses a Kenwood D700 radio that is set to operate at 9600 baud.  A nice feature of this radio is that it has an internal TNC, which made the set up very easy.  I was able to fully check-out the system from my shop (utilizing short distance “test range”) and it operated fine, without any issues.  However, when it was installed at its final location (assessable to a large number of stations), I got reports from stations that they weren’t able to connect or have a successful session with it. 

 

In my limited research into this issue, I’ve found that operating at 9600 baud frequently requires that the TNC be “fine-tuned” (my words) to support this faster speed.  Other operators have informed me that I need to tweak the radio’s “deviation” (?).  I have access to an older model IFR FM/AM-1000S Communications Service Monitor (with unknown calibration) in order to evaluate the radio’s TNC performance. 

 

Can anyone provide me with any good resources or information on 1) how to setup the Service Monitor, 2) what performance parameters I need to be looking for, and 3) what are the TNC settings (and recommended values) for the D700 that need to be changed in order to optimize its performance?  I don’t have a strong RF/electronics background, so I suspect I need this explained simply. 

 

Thanks in advance for any assistance you can provide. 

 

Scott MacGillivray, KM6RTE

Orange, CA

 



Scott MacGillivray, KM6RTE
 

Joey,

 

Thanks for the suggestion.  I now know how to change the radio’s deviation.

 

From: TMD700A@groups.io <TMD700A@groups.io> On Behalf Of qp2trz
Sent: Saturday, October 9, 2021 3:24 PM
To: TMD700A@groups.io
Subject: Re: [TMD700A] Adjusting Kenwood D700 Internal TNC for 9600 Baud

 

The D700 has a service mode you can access with the right set of launch codes.

Google is your friend. 73

 

Joey

VA3GOC VE3XMU


qp2trz
 

No worries.
Glad to help.
PM me with the results.

Joey VA3GOC VE3XMU


John Huggins
 

On Sun, Oct 10, 2021 at 12:02 PM David Ranch <tmd710@...> wrote:

Nice link John.. thanks for that little nugget.  Too bad it's gone off the primary website though.

Jeff's previous incarnation of the Kentucky Packet Network web site was full of lots of tips concerning squeezing the most out of packet gear.  I made my own copy of several important articles before he wiped it to start over.  Thankfully the internet is, usually, forever thanks to archive.org.  If it's packet, the archive is a must read.

John, kx4o