PMRC Digital Education Net
Every Tuesday evening at 1900 (7:00 PM)
QST ****** SPECIAL DEN TONIGHT *****
PhilMont Mobile Radio Club
Digital Educational Net (the DEN)
147.030/147.630 PL 91.5 Hz
7 pm - digi net (No microphones unless emergency)
8 pm - Discussion about upcoming Limerick Drill
We will begin the net tonight with digital mode checkins using THOR 22
Net control will be k3eui or Ny3j (depends on signal quality)
Just checkin QRU tonight (No traffic tonight from members)
After all checkins are acknowledged by THOR 22:
Net control will send a few sample Limerick Nuclear Generating Station Drill Messages from previous drills (2017) using a number of different modes, including MFSK128, THOR 100, 8PSK500F, and MT-63 2K (MT63 modes work using acoustic coupling). I want to see if the receiving stations tonight copy ALL of the different modes (some are faster, some are more robust via a FM repeater).
ADVICE --- Keep your radio's SQUELCH turned OFF at all times
Adjust your receive sensitivity so that the "diamond" in the lower right of FLDIGI (below the waterfall) stays in the GREEN when you are receiving signals from net control. I will begin the net with a long TUNE signal (single pitch signal) at 1500 Hz to allow everyone enough time to adjust their receive audio to the optimum value. If the diamond is BLACK ==> too little audio. If the diamond is RED ==> too much audio.
***** GREEN is GOOD ****
Always open FLDIGI first, then open FLAMP next.
Remember, FLAMP must be open to decode these messages.
FLAMP does not open automatically, like FLMSG.
Adjust the Window location of FLAMP so that you can see it.
Click on the RECEIVE tab (RX) and not the Tx transmit tab.
As you receive BLOCKS of data, FLAMP will fill in.
Missing BLOCKS (if any) will be shown clearly.
Keep your RxID turned on at all times (for mode changes).
All modes will be centered to 1500 Hz (audio pitch on waterfall)
For the purpose of tonight's DRILL, send the net control a REPORT only if you are missing one or more blocks. You will see the REPORT button on the FLAMP Window. No need tonight to send a "CONFIRMATION" (received all blocks on the first pass).
I want to see if within 30-45 minutes, net control can send an EMCOM using FLAMP with different modes without needing to pick up a microphone. The 8PSK modes are fastest, but least robust, so I will do the 8PSK500F mode last in tonight's net.
Again..... the modes should change automatically based on the TxID and RxID coding at the start of each message. You do not need to do anything as the modes change. Keep track of which FLAMPS fail please and report those during the voice net.
At 8 pm, we will have a quick rundown (voice) on how well each station received these messages. Then, we will have an introduction (by voice) of what is involved in the upcoming Limerick Drill (FEMA and PEMA monitors) at the Montgomery EOC. This drill occurs every other year, in November, to simulate an emergency at the Limerick Nuclear Plant (near Pottstown PA)
Each county in the Exercise handles its own EMCOMS.
Townships within a 10-mile zone of Limerick have to provide emergency COMS, hence the introduction of Montgomery and Chester County RACES teams. EMCOMS pass from a central county EOC (emergency operations center) from the Governor's Office to the individual Township EOC's by whatever mode and frequency the hams can use. Tonight's drill will only be with 2m FM (FLDIGI) via the PMRC analog repeater in Roxborough. Remember, these modes, although called 'digital modes' simply use analog audio pitches for modulation. It's sort of like whistling CW into a microphone, except much faster!
The 8PSK modes can go over 3000 words per minute using a standard human-voice bandpass (500 Hz to 2500 Hz).
Chester County has an extensive 5.8 GHz and 1.2 GHz hi-speed system in place and uses 2m FM simplex digital modes as a backup. I've been deployed to two different Townships over the past dozen years, getting messages (FLAMP) via 2m analog audio (FLDIGI).
Montgomery County has a large number of Townships within the 10-mile zone of Limerick. Montgomery County's leaders will make a presentation if they are able to join us on the PMRC DEN by 8 pm. I know a number of DEN member have taken part in the Montgomery County Limerick Drill in prior years, and can add their experience to the discussion.
ALL PMRC folks are invited to join us, or listen in on the discussion.
Folks not yet into the DIGI modes: what you can do tonight
Remember, to RECEIVE digital messages on 2m FM via a sound-card, you do NOT need any special hardware (like a SignaLink or Rigblaster). Just connect a mono or stereo shielded audio cable from your radio's HEADPHONE or EXTERNAL SPEAKER output (1/8th inch) to your laptop's MIC or LINE input jack (often 1/8th inch).
Download FLDIGI and FLAMP (free) and follow the install instructions. In the CONFIG settings you just need to tell FLDIGI which sound-card you are using for the exercise. Your laptop's MIC in port will show up as an option. It really only takes a few minutes to set this up for RECEIVING..... and the software is FREE and works on Windows, Linux and Macs.
I recently heard KB3IV say that he was decoding our digi signals on his smart-phone via his radio. Maybe Ed can share with us how he does this.
At the end of the net, we can coach rookies on how to set this up.
Hope to see you all on 147.030 tonight at 7-9 pm.
Remember, this is a Directed Net. Only transmit when requested.
West Chester PA