Winston Lawrence

KD2WLL - Amateur Radio Notes

Adventures in radio - February 2022

        

2022-02-01 Clearnode changes
Clearnode mods!  Now that the Clearnode firmware update problem is corrected, I still have to run some Yaesu DTMF tests and also tests with accessing YSF and FCS rooms. I also wanted to add a local "News" file to the Allstarlink node - which is probably only for personal use at this time since I have not enabled remote/outside access to the node. I ended up creating two bash scripts.
    1. makenews.sh - which creates the /var/lib/asterisk/sounds/54060/news.txt
    2. the (through tts_audio.sh) /var/lib/asterisk/sounds/54060/news.ul file
    3. and the /usr/local/sbin/saynews.sh which is run by the DTMF command from the radio


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2022-02-04 MD-9600 DTMF and the Clearnode
MD-9600 DTMF! 

I've been using an HT in the car since last year when the Retevis RT73 mobile radio didn't work out as a mobile solution but I've finally decided that I do want an actual mobile radio, not just an HT, in the car. Retevis support confirmed that they couldn't fix the Retevis RT73's missing DTMF function through just a software update so the Retevis is now staying in storage, at least until I sell it. I took the TYT MD-9600, which was my first mobile radio, back out of storage. The MD-9600 went into storage because the 70CM band seems to only run at low power but after thinking the situation through, low-power on the MD-9600 is about the same as high power on an HT. The MD-9600 high power operation is fine on VHF, there is basically no difference from the HT on 70CM. The MD-9600 is the highest powered radio that I currently own and there are very few, if any, 70CM only repeaters near me. In fact, my 70cm usage is primarily the hotspots which are accessed with low power and are working fine. Putting the MD-9600 back into the car should should work well, the only drawback being that it is huge compared to the RT73 and the HT's. I however did need to confirm that the MD-9600 DTMF functions were working. After a couple of trials trying to figure out how DTMF is setup, I verified that DTMF was working..



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2022-02-10 Clearnode changes made permanent
Clearnode mods made permanent!  As an update, my earlier change to add a command to speak the local news file disappeared. Looking into the problem, I realized that changes to the rpt.conf file are wiped out when you rewrite the templates either triggered from an update in the Clearnode app or through a firmware update. This is in fact documented and is a good thing as it makes it harder to "brick" your Clearnode to the point that a reset, firmware update or restore won't recover.

The comments inside the rpt.conf file actually point you to how to correctly make updates, although not really emphasizing why you would want to do this. There are include definitions for files located in the "/etc/asterisk/custom/" directory the files are "/etc/asterisk/custom/rpt.conf, /etc/asterisk/custom/my_private_nodes.conf, and /etc/asterisk/custom/my_dtmf_commands.conf". In this case I added my DTMF command to /etc/asterisk/custom/my_dtmf_commands.conf. Apparently updates, even firmware updates leave the custom directory alone so anything included from their will now also survive updates. Okay, shameless plug for Node-Ventures, you may pay a little more for the Clearnode devices, but the attention to detail and support provided long after the initial purchase are well-worth the price!

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2022-02-16 6m Magnetic Loop antenna
6 meter mag loop revisited!
I noted back in December, that I had put together the Magloop (http://vhfloop.com) 2M and 6M magnetic loop antennas (2021-12-27 2M and 6M VHF magloop antennas). The 2M has been running inside the office since then and has worked out well.
I started to test the 6M mag loop today in preparation for using FT8 on 6 meters. The SWR was at infinity (yikes) and the rig expert SWR meter said no resonance found and to please connect an antenna! Okay so I assumed the antenna was not tuned and I did try tuning it but was not getting anywhere. Finally, I tested the SO239 connector and found it was shorted between the inner brass pin and outer shell so I popped off a note to Bob Leschyna, VE3UK basically saying:

Thanks for the antennas. The 2M is working well and is the 2M antenna in the room. I'm just getting around to play with the 6M now that I have an SWR meter and this Stick Rig Expert 230 says the antenna isn't resonant and to attach an antenna (The 2M gets flying colors 5 stars with the SAME coax cable so it isn't the cable). I tested the 6M coax connector with a multimeter and it looks to me like it is shorted i.e Im getting the same reading when I test the brass pin and brass thread connection and when I test the outside connector to the inside brass pin (or thread) which should show no connection. Is there a part number/name to order that so239 connector as it isn't a standard connector as far as I can tell?

Bob replied within the hour:

Hi Winston.When assembled, you should see a DC or direct short between the center pin and outside coax shield, but to RF it will has an impedance of 50 ohms at resonance.
There are two possible issues. 1) the assembly is wrong, or 2) the antenna is tuned outside of the area you are testing. Keep in mind the bandwidth is very narrow about 150khz and outside of that bandwidth will show infinitely high swr.
Keep in mind a 1/8 turn on the adjustment screws will move you hundreds of kilohertz. It is very sensitive. I suspect this is the issue. Can we have a phone QSO, I can walk you thru it?

That was enough for me to take another look at his excellent here is how you put the antenna together video since the "shorted connection" I had found was actually by design and I replied back

I've got it! I went back and looked at your video again - I may have had the first connection on the coax not properly centered and so shorting out anyway I carefully readjusted, retightened moved the frequency tuning to not quite halfway on the nylon threads and 6m popped up on the SWR meter at 54m (1 star so not good but getting there) I'm still tuning - it's down to 51m and now 3 stars so still working on it but wanted to let you know:-) THANKS!!!

Bob replied back: "Excellent. You should be able to get it down to 1:1. Turn off any antenna tuners. Let me know if you need further help.

The SWR is now 1:1.19 and Im ready to re-setup and try out FT8 on 6M. Amazing support by Bob/Magloop particularly for a sale that was made two months earlier. I would definately recommend and purchase from Magloop again



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2022-02-18 Learning CW - 01
Learning CW 01 - Getting started!

The items on my original ham radio to-do list were:

  1. Get Technician License
  2. Get a radio and get on the air
This expanded to:
  1. Get Technician License
  2. Get a radio and get on the air
  3. Get General license (mostly for the long distance communication options)
  4. Learn CW

With the first three items now checked off, "Learn CW" was the next "milestone event". I joined the Long Island CW Club as it seems to be a highly recommended way to do online CW training. I took my first "intro" class, explaining how to use the folders, website , Zoom etc. They did ask if I had a CW key and I told them I had an MFJ-557, taking that in stride, they recommended getting a better key if possible but to at least run the device off a DC power supply instead of batteries in order to improve the sound. The initial focus for the beginner classes is on learning the alphabet and not sending so no rush on getting the key. I had picked up the MFJ-557 at a LIMARC virtual hamfest auction last year and yes the oscillator sounds terrible but I can use it as just a straight key by disconnecting the oscillator.
A quick order to cwmorse.us (last week) landed me a My-Key-Mouse USB interface between the straight key part of the MFJ-557 and the USB connection on my computer. I had to make a 3.5mm to bare wire connection (for the key interfce) and it took a little fiddling around with the recommended software Morse Keyer V4.3 (Windows) to get the whole thing working.


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2022-02-27 LIMARC Hamfest

I went to the LIMARC hamfest this morning, my first actual, in-person hamfest. I told my wife about it and she decided to come with me since it was a cold, but otherwise shaping up to be, nice sunny day. She knew I didn't know anything about the hamfest, but, "I guessed" it would be like a flea market for ham radio stuff. I think she was a little curious how the hamfest would compare to the field day which we went to last year. She probably also wanted to make sure I didn't come home with anything like the antenna towers that she also saw on field day. The hamfest was slated to start at 9:00am and we got there about 9:20am. We left by about 10:00am. Sorry, this was not a very good hamfest. More than half of the stuff for sale was not even ham radio related. We saw things like masks, lights, fans, bug sprayers and even dolls. There was also a lot of CB and walkie talkie type gear and stuff so ancient I couldn't tell what I was looking at.

My main reason for attending was to pick up some connectors and maybe an antenna to fit my lip mount TRAM. We ran into Frank (KC2ZOR) from the local radio club RCARC, and he was the only person there that we knew. Frank actually came over to us to say "hello", recognizing my wife, if not initially me, from field-day. Wearing a mask, newsboy cap and a heavy hoodie *I* probably woudn't have recognized me from a one-time field-day meeting. Since I joined RCARC the club is still doing online Zoom, rather than in-person meetings.

Anyway, Frank said that the connector table, usually there, was a no-show this year. Frank had also come to pick up some connectors and cables so I don't think he was real thrilled about the turnout either. Anyway my wife and I did one more circuit around the tables. I picked up three boxes of (hopefully not fake) KN95 masks for $1.00/box and then we left.

I did stop at Guitar Center on the way home and picked up some audio cables and a pre-amp/mixer so the morning wasn't a total waste.


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'73 from KD2WLL - the adventure continues