Sunday November 5, 2023 – VarAC

Thanks to VA7PX and VE7JEY for doing feasibility testing the past few days. Below is what we learned, some of it already posted in discord, channel FT8/VARA.

The significant finding:

Broadcasts are async messages using  AX25  packet protocol similar to APRS . Broadcast does not have a delivery guaranteed mechanism like a vara link so it needs a greater signal strength, probably SNR -5 or higher. not good enough for us. That functionality may not be hopeful.

Any stations can broadcast but it is clear that only a few or no local stations will hear the broadcast. Those who broadcast and hear a reply please record or take a screen shot of the broadcast window at the end of the session to share on the discord channel Thanks. Note that while in broadcast mode you can not connect P2P with another station.

P2P CQ. We can only CQ each other using  CQ slots (10 available) for one to one chatting. So we can have a maximum of 10 P2P connections at any one time  on the 7.120 Mhz frequency. We can see who is present with beacons and check connectivity with pings before making a contact. Contact P2P is best done from CQ calls which indicate the slot selection that everyone can see.

Vmail: Vmail is a great tool for fast short text and can be done on the main frequency (no slot) by contacting a station you can hear from the beacon window. You connect to it from the right click option. Later on we will need to learn how to use the parking (mailbox) option where your vmail can be stored to a third station to hold it for the recipient you can not hear but the third station can. This is a more advance feature and we need to learn how to use.

PSK reception reporter map. Please at the end of the session go to PSK reception reporter map, In display option (beside (go) check show SRN, then select 40m, sent/rvd,  your callsign, using VARAC, last 15mn, 30mn or 1hr accordingly and make a screen shot of our local region and share in on discord =>FT8/VARA channel. Thanks.

Like FT8, VARAC use the Upper Side band of the center frequency on all the bands, including lower Bands so if your radio does not have a Data mode you will have to set your radio to upper side band manually on 40m. Also set up your radio audio filter to 2300Hz (NOT VARAC) which is needed for slots. If both stations only use the center frequency (no slot) you can use a 500Hz filter on the radio which will reduce the noise lever and may increase reception quality, (great for vmail transfer on the main frequency when SNR is low (below -20) if needed.

We learn as we go so patience and perseverance is the key.

Thank you for participating in this experimental net.