The PMRC Digital Education Net

PMRC repeater: 147.030 PL 91

A voice and data net to discuss digital modes

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.

TU all,

Barry  k3eui

West Chester PA


Allstar is a voice over IP communication mode based on the Asterisk PBX platform.
An analog type transceiver is connected to other Allstar nodes via the Internet.

Doug, WA3DSP, developed the code to run Allstar with an inexpensive Raspberry PI.

For more information see:

Thanks to Doug and the Philmont club for setting this up.


If anyone is interested in HF NBEMS nets there is a group called Pa NBEMS Net

To join the group click here: PA NBEMS

NBEMS stands for Narrow Band Emergency Messaging System.

The Pa NBEMS Net meets every Sunday morning at 0800L using Fldigi at 3.583
Barry, K3EUI, is the net manager.

We would like to see more participation from the DEN members.