In an earlier post HERE I described how Corne ZS1COR wanted to connect via ZS1I GRHub Network to the ZS2PE-R Network. This time around Corne wanted to extend the coverage area of the GRHub Network by installing a RF VHF/UHF Radio Link via Echolink in the George area. Now I am sure that you all know this could be achieved quite easily by just adding a SignaLink interface between the computer and radio. With the current price of this interface it is out of reach of many radio amateurs in South Africa. Corne already had a homebrew USB Soundcard Interface for digital modes but this was only for digital modes and not for voice according to the constructor of the interface.
Image: ZS1I Mini Soundcard Interface donated to Corne ZS1COR.
I scratched around in my junk-box and found an old homebrew serial sound card interface that I developed and build many years ago. It would be a long-shot but it must just work. Corne arranged for the pickup and no sooner than he received it he indicated that he needed help to setup the interface. When I still manufactured ZS1I Sound Card Interfaces for radio amateurs to purchase, I also compiled a setup manual that allow a person to successfully install all the necessary. The manual and diagram was send to Corne via Telegram. Corne could not wait and immediately started to setup the unit only to find that it stays in PTT mode, the reason unknown. You could hear the disappointment in his voice. OM Danie ZS1DBJ offered to help but they still could not get the unit to work. I then suggested that Corne use the VOX of the Echolink program just for the interim until such time as a dedicated interface was constructed.
Now VOX is definitely not to be used on a permanent link to the GRHub Network or for that matter to any permanent connection to any VOIP Network. I am sure I need not explain all the caveats of VOX. Let just say it is unreliable, can cause havoc etc. etc. The correct way would be to use a dedicated radio, soundcard fob and computer. The Echolink software needs to interface to the radio in order to control Push To Talk (PTT), recognize when a signal is present on the radio (COS) and also manage the TX & RX audio streams between the computer and the radio. All of these functions are achieved using a USB sound card fob that plug into to the computer's USB connectors . The connections to the radio however require wired connections.
As you might expect the RX & TX audio are already part of the sound card as this is the intended function of a sound card. RX audio goes to the Microphone input and the TX audio comes from the sound output The sound card chip inside the fob has some extra GPIO abilities that we need to tap into for PTT (Push to talk) signaling and COS (COS – “Carrier Operated Signal”, “Carrier Operated Squelch” or “Carrier Operated Switch” or COR Carrier Operated Relay… all the same thing, just different names). Between the fob and the radio some simple addition circuitry is needed. Here is an image of the soundcard fob that I constructed and currently use with the ZS1I AllStar node.
Image: Heavy modified Syba UCM119 Souncard as used with the GRHub Network
Various commercial soundcard fobs are available from overseas suppliers but as I already stated are rather expensive to import. The above unit is really fail safe and works great. The USB Soundcard was imported for R143.00 per unit. The soundcard is called a Syba UCM119. Enough about sound fobs.
Let get back to Rocking n Rolling! Yes, we had a great session of Rocking n Rolling on the GRHub Network starting 11 December 2021 in the afternoon and ending on the 12 December 2021 early evening. What is this rocking and rolling about? Well it sounded like rock and roll on the network as Corne ZS1COR was experimenting in setting up a VHF/UHF RF Link via Echolink to the GRHub. After literally spending the whole of Saturday afternoon and evening trying different settings and getting advice from yours truly but the end result on the 11 December 2021 was not good.
Unfortunately he could only "play" with VOX in getting the link to work. After some tests on the VHF band it was established that interference in George was so bad at his QTH that VHF was unusable. It resulted in all sorts of rock and roll sounds combined with his voice audio. One should remember that Corne is fairly new to amateur radio and that he did all the tests, settings and experimenting alone in his shack. He tried several options but to no avail. Bad audio and lots of rock and roll sounds was heard on the network.
Sunday started of with the same bad audio and rock n roll sounds. No improvement after trying several connections and settings. Just after 16h00 Corne decided to give UHF a try as he discovered that there was no interference on UHF at his QTH. He used 435.400 Mhz and it was not long before clear audio was heard with no "rock and roll" sounds. The "rock and roll" changed to great amateur radio audio. Now one should remember that settings had to be made on Echolink, RF Radio, Laptop Computer and the Soundcard Interface to ensure that all the equipment "plays ball" to enable clear good audio.
Image: GRHub Network connection log for the past Saturday and Sunday
Corne was once again "on fire" but he wanted to test with radio amateurs in George. It was not long before Michael ZS1MMB and Keverne ZS1ABU joined Corne while yours truly monitored the GRHub Network to listen on all the nodes and links for good audio quality. I can confirm that great audio was forthcoming from all three radio amateurs in George. They chatted away for a lengthy period about how Corne successfully established a new GRHub Network RF and Echolink link. Quite a few questions were forthcoming and answered. I for one was very happy with the quality of audio forthcoming from all participating stations but as already stated this setup should not be used for a permanent link setup.
All talks ceased early evening after a long and tiresome weekend of testing, disappointment and finally success and excitement. I would like to thank Michael and Keverne for assisting Corne in testing his link setup. I was able to evaluate the link audio and other connections on the GRHub while the three of them were chatting. It was clear that everybody had a "ball of a time".
Once again the "bull fighter" was hard at work and it resulted in a great and successful "fight".
I want to congratulate Corne ZS1COR in succeeding in setting up a temporary link from George to the GRHub Network, Mossel Bay for use by radio amateurs in the George area.
VOX is not ideal for a permanent connection to the GRHub Network but it can be used as a free standing option with supervision. After the festive season we will be looking at setting up a fairly fail safe link connection to and from George.
Stay tuned!!
