1. Press PTT, wait 1-2 seconds before speaking and wait
1-2 seconds before you un-key.
You never know how a ‘spot’
or a repeater may connect to TG555. It
may be satellite, cellular, or a terrestrial service. Satellite and cellular will introduce
additional latency into the flow of traffic through the reflector. Adjust as
necessary based on the latency you experience. A quick PTT can in some cases cause the
first part of your transmission to be lost. Wait a bit before you release the
PTT button to ensure the last syllable of your sentence is passed through the
reflector.
2. Soliciting a call.
Call more than once if you
want to be heard. A single call might
not be heard or recognized. I notice
this frequently where someone keys up, says something, but I did not pick up
what was said. Please observe proper
repeater etiquette for monitoring and directed calls. If you ‘quick key’ and say your call it may
not pass your audio through the reflector (See 1 above).
- Directed call:
A directed call is one where
you wish to speak to a specific operator.
Say the call of the person you are trying to reach then say your call (his call – your call). If you say your call first, then you are
calling yourself while using another operator’s call sign.
Examples where W9KLS calls
W4NOC: “W4NOC this is W9KLS”, “W4NOC from W9KLS”, “W4NOC this is W9KLS
calling”, “W4NOC W9KLS”.
- Monitoring call:
Use this method when you
wish to let others know you are available for a QSO. Examples: “W4NOC listening”, “W9KLS
monitoring”. Calling CQ on a repeater
(or P25 Reflector) is not recommended.
3. Wait 2-3 seconds between transmissions.
This accommodates the delay
and allows another station to join. The
P25 Reflectors operate on a VPS in a data center. Latency is <1.5ms. Delay
through the reflector between stations is <1 second ‘P25 Repeater to P25
Repeater’ and about 600ms between ‘two hotspot’ users. Additional software processes in the
conversion from analog through the 419762 to the TG555 adds as much as 1
second.
4. Analog Asterisk/ASL nodes that connect to the TG555/419762
ASLx P25 Gateway should disconnect when finished.
We don’t want to receive an
angry email from the operator of another Asterisk/ASL node. TG555 is always connected to 419762.
There is a link below to see
what if any other Asterisk/ASL nodes are connected to 419762.
5. Transcoded analog to digital audio can be
unreadable if the received signal to the repeater is weak.
If your audio level is hot
or signal quality into the repeater is poor, these issues are magnified when
transcoded. Proper adjustment of the
audio settings in a P25 radio is also important. Hot P25 audio may sound slightly distorted to
another P25 radio. But to a ‘spot’ or analog user, it will be muffled and
distorted to the point it may be unreadable.
P25 repeater users or ‘spot’ users should connect to the parrot (P25
TG10) and listen to your audio.
6. Internet latency and delay introduced by
transcoding can vary. It requires some
practice to get used to it.
Enabling SmartPTT prevents doubling. Using
recommendation 1 above is also important.
7. Please identify by voice.
Remember to identify every
10 minutes. An ‘unidentified
transmission’ is considered illegal.
When closing a QSO with an international station, you must sign off by
giving both your call sign and that of the foreign station.
1. Why is an incorrect call sign or just numbers
displayed?
If the P25 signal is weak into the repeater,
the DMRID may be garbled and incorrectly decoded. Here is an example.
2. Why is an 'r' shown under the Gateway column?
This sometimes occurs when a
P25Gateway disconnects from the reflector. Why? I dunno.
In the example below,
seconds and milliseconds of the time stamp 10:54:44 was parsed into
the “Target” column and the transmission record is shown under ‘Gateway’ at the
moment the radio keyed up and steered the repeater P25Gateway to a different
reflector. The ‘r’ follows.
|
Target |
Gateway |
|
|
R |
|
:54:44 |
2Ř23-Ř9-26 14:54:44.83Ř Transmission started from W4NOC NB |
3. Why is my call sign not displayed when connected
to the reflector through the ASLx419762 P25 Gateway?
Asterisk/ASL does not know your
call sign. So it is not passed through to the P25 Reflector or to P25 radios or
hotspots.
The call sign of the
Asterisk/ASL node 419762 (W4NOC) will be displayed.
4. Why is the first or last syllable dropped?
Please read Recommended
Operating Procedures; 1 and 2.
5. I keyed up, threw out my call, but did not get a
reply.
Delay is introduced by the
software, hardware and the Internet (VPN, Cellular hotspots, Wi-Fi).
A 2-3 second key up may not
pass audio through the reflector. No one will hear you.
I have witnessed this while
tailing the logs with my XTS2500 on the desk beside me.
Read Recommended Operating
Procedures; 1 and 2.
6. Why did the reflector dashboard loose the Last
Heard and All Heard data?
The logs rotate at 00:00 UT.
The P25 Reflector is running on a Pi 3B+ limiting the ability to store logs.
7. How can I tell what Asterisk/ASL analog nodes are
connected to the P25-ASLx419762?
Connected node numbers are not
passed through to the ASLx-P25 Gateway. So, it cannot be displayed on the P25
Reflector Dashboard. Allstarlink Stats for 419762. Also see Stan’s Supermon
(Asterisk-ASL nodes).
8. Why do I hear the call sign or telemetry from an
Asterisk/ASL node other than W4NOC?
Telemetry on Asterisk/ASL node
419762 is suppressed and will not propagate to other nodes.
Asterisk/ASL telemetry
(CWID, audio announcements, bing and bongs) with exception of an emergency MUST
NOT propagate to other nodes!
It is an easy fix and well
documented in the allstarlink and dvswitch-server forums.
9. Why can't I connect to P25 TG555?
Using the INTERNET for
linking repeaters is not as reliable as you would expect. We do our best to keep the cellular hotspots
at the tower working and the VPN operational. When something fails, we resolve
it as quickly as possible. Using
cellular data as the transport medium for analog or digital linking is severely
flawed and unreliable. Cable ISPs are
no more reliable than cellular. I long
for the days when we could link repeaters with RF. But that is not practical and cost
prohibitive with TCPIP linking over long distances.
10. Are you using PI-STAR?
PI-STAR images are
outstanding for spots and MMDVM repeaters. The repeaters on this network are
Quantars. The PI-STAR team registers the
P25 Talk groups and distributes the P25Host files we all depend on. The x86 LINUX servers supporting the
repeaters are running the Asterisk/ASL2.0.0-6B DEBIAN-BUSTER image and
DVSwitch-Server. The P25 Reflector and
ASLx-419762-P25Gateway is a Pi3B+. It is running Asterisk/ASL2.0.0-6B
RASPBIAN-BUSTER image and DVSwitch-Server.
The P25 Reflector was compiled on the same Pi3B+ from source available
from noStar and the P25 Reflector Dashboard is courtesy of M0VUB.
11. How do I connect to TG555?
Any device with a P25Gateway
can connect to TG555; P25 Repeaters a networked P25Gateway, spots,
droidstar.
12. I selected TG 555 with my radio and my local
P25Gateway did not connect to TG555.
If you are on one of our P25
repeaters, they Startup on 555 and will respond to TG requests from your
radio. This is not true of all P25
repeaters. Check your radio
programming. Try a different TG, like
10200
13. How do I change talk groups through 9271375,
9277375?
Programming radios is a
lengthy topic. There are a couple of
ways to accomplish this with XTS, XTL radios.
My preference is to create a TG list containing a few talk groups; 555
Ga900p25, 10200
14. Is it OK to use talk groups other than 555
through 9271375 or 9277375?
Yes. The P25Gateways on these repeaters are active
and will accept TG requests from your radio.
If you do link to 10200 or another talk group, please select 555 on your
radio when you are finished with 10200, key up once and that will reconnect the
repeater P25Gateway to 555. The
P25Gateway should timeout after 10 minutes of inactivity on the other TG (such
as 10200) and reconnect to the assigned Startup, 555.
15. Is there a P25Reflector (Talk Group ID) for local
traffic or station-to-station through your repeaters?
Station to station traffic
always works. The P25Gateways associated
with our repeaters by default connect to 555.
They may be temporarily disconnected from any talk group or they may be
connected temporarily by a user to other talk groups such as 10200
16. Are nets permitted on this reflector?
Yes, weekly, bi-weekly,
monthly is fine. Go here to coordinate
a net on TG555 or other repeaters in this network and discuss it with
Stan. Monday and Friday evenings are not
available at this time.
17. I don’t have a P25 radio or a spot at this
time. How can I connect to the reflector
to experiment with P25?
A frequent member of the
TG555 group KD8VHU told us about DroidStar.
Great tip! It is the absolute easiest way to use your Android device to
connect to TG555 and experience P25. The
audio we hear over the P25 repeaters from DroidStar Android users is very good. It is a great way to try P25 before you
buy.
18. What is the best radio ‘spot’ to buy or build?
If you are building it
yourself, the pi-star/mmdvm hat/radio modem.
All you need is a Pi, simplex MMDVM Hat (radio modem) and of course a
digital radio (P25 or Yaesu C4FM). I built
my homebrew pi-star spot for about $70 with a used Pi (1) B+ from eBay and a
MMDVM hat from Amazon ($23 right now).
There are several commercial products on the market including ‘ready to
use’ Pi-star/MMDVM_Hat models in a nice case. Here is a picture of a simple
homebrew spot and a video. A video of the same homebrew spot with a fan.
19. I’ve tried P25 with my ‘spot’ or DroidStar and
I’m ready to buy a P25 radio. How do I
select a radio?
Research and ask questions
before you buy. We have operators using
Motorola XTL, XTS, APX and Astro Digital Spectra. Consult batlabs, repeaterbuilder, or
radioreference for information. Look up
the model number of the radio, get the flashcode and de-code it to make sure it
can operate P25. Motorola XTL or XTS
radios may have a ‘conventional only’ flashcode even though advertised as
P25. Consider how you will program the
radio. You will a need programming cable
and the programming software.
20. Do all repeaters in this network operate P25?
The 927.1375 and 927.7375
are operating P25 and analog (mixed mode).
Both are ‘networked’ and have working P25Gateways. 442.125 is a P25 repeater but not yet
‘networked’ to a P25Gateway. By 1Q-2023
all three repeaters will operate P25 with functioning P25Gateways. 146.715 is analog but may be connected to the
TG555 over the TG555/Asterisk/ASL419762 bridge.
21. I have a question about Raspberrry Pi?
Please reach out to Stan
KI4FVI.
22. I have a question about yaesu f u sio n radios
and using the MMDVMHost YSF2P25?
Please reach out to Chris
K1KC.
23. I have a question about pi-star?
Throw out a question on the
reflector. The collective knowledge of
the 555 user group is impressive. Share
what you know and ask questions.
24. Can my Open Spo t3 (or 4) connect to
private/local P25Reflector?
Yes it can. I can lead you through it but it is best to
consult the Help. Changing TG with your
radio through the OSpot is inconsistent.
The use of terms is confusing and incorrect. Contrary to the ‘Help’, SelCall is not
supported by the P25Reflector. I have no
idea what TG9 is used for and the common Parrot TG10 is not used on the ospot. Instead they picked the UNLINK TGid 9999 to be
the Parrot or ‘Local Echo’. Go
figure!
25. How much cellular data will my spot consume?
On my test trip, I traveled
for 7 hours with my pistar based spot connected by Wi-Fi to my cell. The phone recorded 29Mb data usage and the
cellular provider recorded 23.49Mb data usage.
Obviously I did not talk the entire time, but I did use it frequently on
that 7 hour trip.
26. Why did the node I connected to 419762 disconnect
automatically?
Beginning February 27th,
2024 the link inactivity timer (rpt.conf) is enabled on 419762. It will disconnect all nodes after 10 minutes
inactivity. The inactivity warning
message will not play.
27. I cannot connect my Clearnode to some P25 talk groups
or to TG555?
You may need to update your
P25Host file. DVSwitch-server which is
the basis for this device includes a script to demand updates to the DMRid list
and the host files. Refer to the
seller’s documentation to run the DVSwitch Mobile DVSM_Update script. The P25Host file is a lookup table that
points the user selected TG to a domain name and UDP port. The master P25Hosts is maintained by the
PISTAR group. Your list of registered P25
talk groups should match this list.
28. What steps can I take to resolve broken or
distorted audio; drop-outs, switching talk group, no callsign displayed,
garbled?
Pistar based hotspot users
should use the pistar-mmdvmcal and monitor the web console for ‘Loss’ and
‘BER’. Calibrating your portable radio
to your particular hotspot MMDVM radio is essential. Don’t assume that every radio you own will
calibrate the same. The ADF7021
transceivers used in most MMDVM radio boards do not respond well to high power
levels from your portable hand held radio.
I have noticed myself that if I use my mobile P25 radio transmitting to
the ‘spot’ high BER and Loss occur even with the mobile set to low (16W). If you receive reports of drop out, garbled,
‘R2D2’ or no callsign displayed, you may wish to check your calibration and
power level. Those connecting to the 555
through repeaters will normally only experience issues when operating in areas
where coverage is weak. But they are the
same issues. On occasion the issue can
be associated with the Internet quality at the repeater sites or the VPN
between repeater sites. It may not be a
problem with your equipment.
This example may be due to
poor Internet quality, Wi-Fi issues, radio not calibrated to the MMDVM radio
board, excessive power from the user’s radio, too far from, or too close to the
‘spot’. The audio heard by other uses on
the reflector during this period was broken, distorted, with drop-outs, and at
times no callsign is displayed. If you
would like to see your traffic for a given period, please provide the date and
time UTC and an email address.
M:
2024-01-22 09:14:29.026 P25, received network transmission from ‘call redacted’
to TG 0 (TGID
error)
M:
2024-01-22 09:14:31.663 P25, network end of transmission, 2.7 seconds, 17% packet loss (High Packet Loss)
M:
2024-01-22 09:16:46.436 P25, received network transmission from 0 to TG 0 (DMRid/RadioID corrupt, TGID error)
M:
2024-01-22 09:16:49.398 P25, network end of transmission, 3.4 seconds, 16% packet loss
M:
2024-01-22 09:17:05.995 P25, received network transmission from ‘call redacted’
to TG 555
M:
2024-01-22 09:17:08.338 P25, network end of transmission, 2.7 seconds, 7% packet loss
29. Other users on the 555 report hearing carrier and
seeing my call, but no audio when I transmit from my Ya e s u radio to my
‘spot’ (YSFtoP25)?
Make sure your radio is set
to VW (Voice-Wide).
30. How do I create a private or local talk group in
my spot?
That’s a lot to address
here. For DVSwitch-server users (such as
clear node or Analog_Reflector) it is easy.
Go to /var/lib/mmdvm and edit (nano) the file private_P25Hosts.txt. Add for example this tab delimited line: ‘7 georgia900p25.us 41001’. Then type ‘sudo
systemctl restart p25gateway’. Private
or Local P25 Hosts should be limited to the numbers 2-5,7-8. For PI-STAR users, this describes the procedure. Some users report their ‘spots’ cannot use
private or local talk groups (see question 24). You may wish to discuss that limitation with
the manufacturer.
31. Who registers P25 Talk Groups or Reflectors?
PI-STAR manages the registry
and makes the list of reflectors or P25 Hosts available to all P25 Gateways
(spots, USRP clients, P25 repeaters, MMDVM repeaters). Instructions to register a new reflector are found here.
32. My radio is not recognized by the spot when I
transmit or my BER is high (>1%)?
Something may be off frequency,
WAY OFF. Frequency error is the root
cause of most of these issues. Use the
pistar-mmdvmcal. Don’t be surprised if
your spot or radio is off frequency, or both.
I have seen spots that have >1khz frequency error. The worst one was the most expensive. The TCXO used on some MMDVM radio boards
(MMDVM_HS_HAT or MMDVM_HS_DUAL) may be inferior. Portable radios are notoriously off frequency
as well. They may worsen as they age.
Don’t be afraid to adjust the offsets in MMDVMHost. I have a couple of MMDVM hats. One is spot on, the other has a frequency
error of -124Hz. But I can say that both are stable. Temperature variation inside the enclosure
and inferior TCXO definitely affect stability and accuracy.
1. How is the analog to P25 audio quality?
The answer is ‘pretty
good’. Good quality analog into the
repeater will transcode well to P25.
Poor quality or weak signal audio into the repeater can be unreadable
when transcoded to P25. Node 419762 is
connected to a repeater node in
2. Can I improve the P25 audio quality of the XTS2500
under high background noise conditions?
When you are operating in a
noisy environment, the NMN6193(B/C) noise canceling microphone will resolve the
problem. Thanks to KD8VHU for the recommendation.
Thank you for using
W4NOC
KI4FVI
W9KLS
K1KC
7 April 2024
Suggestions and corrections
are appreciated.
