20m Expedient Dipole Setup Time

Link to PDF: 

https://drive.google.com/file/d/1eOGgBRNniupQ_lcg2iT2oVDQsbLWOPrz/view?usp=sharing

TX Delay of Modern Radios 2016

I am playing with 9600 baud packet.  TX delay is a big issue, or more importantly can dramatically reduce throughput .

TX delay is the time it takes for the radio to go from listening to transmitting RX to TX.

What are the TX delay numbers of off the shelf ham radios in 2016

Kenwood V71    -   62-75ms
Icom 880            -   46ms
Icom  2820H      -   43-49ms
Yaesu 7900r       -   96-122ms

Slightly older Radios:
Kenwood TM V7A  -  50ms
Kenwood G707A     -  50ms

Baofeng and Signalink

Signalink makes a cable to connect a Baofeng or Wouxun or Kenwood HT to their nifty little box.  The cable is called a SLCABHTW.     One of the nic things is the internal wiring is the same as if you are using the 6 pin DIN connector and you can use the SLMOD6PM jumper module with it.

If used with direwolf and RMS/Express it is plug and play.    If you are using the Baofeng/Signalink combination with FLDIGI you need to tell FLDIGI to make sure in
Configuration->Sound Card->Right Channel you have "Modem signal on right and left channels" selected.     With that, life is great.

Low transmit Volume using the Signalink and TM-V71

I had a problem with low transmit volume when using the Signalink USB sound card connected to the Kenwood TM-V71 radio.   Played with all sorts of settings and then found the problem buried in a Signalink FAQ.

When using the Signalink for 1200 baud packet make sure you DO NOT have the radio set for 9600 baud.   It works, but the transmit audio is very low.   I could hear the transmission on a radio wight the volume turned most of the way up but when the 9600 baud settings were taken off, the transmit volume went what I considered normal.

The Direwolf software TNC shows the audio level of each packet heard.   With 9600 baud enabled on the V71 the level was 2 - 3.    When 9600 baud was disabled on the radio, the audio level went back to 25-30  so it is not just subjective.

Remember,  this is for 1200 baud packet.   Your milage might very if doing something different.

RMS Packet Gateway experiments Windows Version

How to set up an RMS Packet Gateway.  

First of all you have to register it.  I am not there yet since I am still in an experimental stage.  I want to understand how it works before I get it registered and known to the whole world.  I also want to get it right.   The permanent installation will be linux based (I think).   But the easy way to understand the technology is to put up a windows implementation and get a base understanding.   I followed the instructions closely and I got it to work.   These are the two models I have working on the bench reliably.

RMS Relay is normally not necessary.  But in this case since I was not going to register the test setup and I wanted to mail to stay local, RMS Relay gave me that option.

Now that I have something reliable working as a model I can move on to getting the software running in a more permanent configuration.   The hope is that I can get the right Hub/Host software running on a Raspberry PI and go from there.

Kenwood TH-72D TNC Hint

Well I am doing a comparison between the software TNCs , Direwolf, UZ7HO sound modem, AGWPE and have introduced the Hardware TNC that is built into my Kenwood TH-72D handheld unit.     It was fairly easy to move from doing APRS to being a KISS TNC.   Just press the TNC button on the front panel until you see the message move from APRS12 to PACKET12 and make sure the USB port is on and you are set.  

Weird problem is that it would work intermittently.   Worked pretty well and would drop loose a packet or two and work again.    I wound up looking at various setting and then turned off the GPS and everything started working perfectly.     I am guessing the GPS was adding some data to serial stream and corrupting some of the AX.25 packets.  

So the hint.    Turn off the GPS if using the unit as a generic TNC.

What is Winlink?

A new video has been released.  It is pretty good for people wanting to know what is winlink

https://youtu.be/qGhUfW8pjY8