Re: TT4 well configured as a Digi????
thanks Rob for the answer,
i was away to read my email from the hospital.
the chinese radio,its the only one i have around,i know they are not the best but i do what i can with what i have here.
i will follow your comments
thanks again
gervais ve2ckn
The latest firmware fort he TT4 is Alpha v0.72 and can be downloaded from
.
Configuring the DIGI is more dependent on RX and TX settings that on any specific DIGI setting.
These are very specific to the equipment in use, so someone elses configuration will be of little use.
Also, HTs are probably the hardest to confure for RX, and the Chinese versions tend to be even more so because of their squelch configuration.
As far as the actual DIGI settings, since you really are trying to get data to your home station I would go with
?? ALIAS1 WIDE1
?? ALIAS2 WIDE2
?? PREEMPT TRUE
That should cover all the packets your setup hears.
NOTE:? The TT4 would accept ALIAS1 WIDE and ALIAS2 empty would take care of DIGI'ing all heard packets, but I prefer to use specific WIDE# settings and limiting them to WIDE1-1 and WIDE2-n.
I am not sure what you mean by "login".? You will likely need to connect to the TT4 from a computer and use a terminal program (like PuTTy or TeraTerm) and follow the instructions in the Quick Start Guide (also at the above Tinytrk4 link.
On Sunday, July 11, 2021, 4:37:52 PM EDT, Gervais Fillion <ve2ckn2@...> wrote:
hello everyone,
i am not sure at all that my TT4 here is well configured as a digi,
what is the latest software that is running in today tt4 ,i would compare with the one i have here and
is there a gentleman here that could send me his file of an actual well working tt4 as a digi!
it has been month since a login in the tt4,,i dont remember even how to do it but i remember it was special,,i will check if i can find it.
this tt4 here will be installed in a tree with a small solar panel and a checp chinese talkie.it will re-send to my igate the traffic that i cannot hear because i am badly located,,in a very
low level terrain and surrounded by small lountains so i can hear just a bit the traffic.this tt4 should be a big + and i need just 1 watt max so its great.
73/s all and thanks for your help
ve2ckn2 at hotmail.fr
gervais ve2ckn
|
Re: TT4 well configured as a Digi????
The latest firmware fort he TT4 is Alpha v0.72 and can be downloaded from .
Configuring the DIGI is more dependent on RX and TX settings that on any specific DIGI setting. These are very specific to the equipment in use, so someone elses configuration will be of little use. Also, HTs are probably the hardest to confure for RX, and the Chinese versions tend to be even more so because of their squelch configuration.
As far as the actual DIGI settings, since you really are trying to get data to your home station I would go with
?? ALIAS1 WIDE1 ?? ALIAS2 WIDE2 ?? PREEMPT TRUE
That should cover all the packets your setup hears.
NOTE:? The TT4 would accept ALIAS1 WIDE and ALIAS2 empty would take care of DIGI'ing all heard packets, but I prefer to use specific WIDE# settings and limiting them to WIDE1-1 and WIDE2-n.
I am not sure what you mean by "login".? You will likely need to connect to the TT4 from a computer and use a terminal program (like PuTTy or TeraTerm) and follow the instructions in the Quick Start Guide (also at the above Tinytrk4 link.
On Sunday, July 11, 2021, 4:37:52 PM EDT, Gervais Fillion <ve2ckn2@...> wrote:
hello everyone,
i am not sure at all that my TT4 here is well configured as a digi,
what is the latest software that is running in today tt4 ,i would compare with the one i have here and
is there a gentleman here that could send me his file of an actual well working tt4 as a digi!
it has been month since a login in the tt4,,i dont remember even how to do it but i remember it was special,,i will check if i can find it.
this tt4 here will be installed in a tree with a small solar panel and a checp chinese talkie.it will re-send to my igate the traffic that i cannot hear because i am badly located,,in a very low level terrain and surrounded by small lountains so i can hear
just a bit the traffic.this tt4 should be a big + and i need just 1 watt max so its great.
73/s all and thanks for your help
ve2ckn2 at hotmail.fr
gervais ve2ckn
|
TT4 well configured as a Digi????
hello everyone,
i am not sure at all that my TT4 here is well configured as a digi,
what is the latest software that is running in today tt4 ,i would compare with the one i have here and
is there a gentleman here that could send me his file of an actual well working tt4 as a digi!
it has been month since a login in the tt4,,i dont remember even how to do it but i remember it was special,,i will check if i can find it.
this tt4 here will be installed in a tree with a small solar panel and a checp chinese talkie.it will re-send to my igate the traffic that i cannot hear because i am badly located,,in a very low level terrain and surrounded by small lountains so i can hear
just a bit the traffic.this tt4 should be a big + and i need just 1 watt max so its great.
73/s all and thanks for your help
ve2ckn2 at hotmail.fr
gervais ve2ckn
|
The primary reason for this is the? high power unit that I have.? This is meant to be a digipeater primarily - not just a fill in digi - during a disaster response.? ? As this is for SATERN we do not know exactly how much of an APRS network may be in place -? So being able to change this unit from being a Full Fledged Digi to provide that service? to a "tracker/fill in digi" is ideal.? Changing the paths, icon, status message to reflect stationary/tracker etc would be beneficial.? ? ?And depending, might be able to help us reduce traffic clutter on the high power unit in an area that might be more saturated with APRS than my area.? As these are SATERN assets, they may be requested and deployed around the country without me. :)? So my idea would be to make it easy for this unit to be dual purpose.? "Turn the switch this way to serve that function and turn it the other way to do this"? ?The other three.. only do "this".? ?
Yes, both Banks settings would be set to use Smart Tracking but one would be a digi with a stationary type Icon, while the other would be setup like the 3 lower power units.? ? Its mostly having the option to do it if we decide it's beneficial.? ? The issue with change settings is that there are too many people who will just go in and play.? If the units go with someone who understands them, great.. and there is always that one person who has to tweak it and screws up something else.? ? Allowing a change in mission settings with the push of the button may be our better choice.??
With my two TT4 Port-a-digi / trackers, they are all self contained?and have their own battery to run everything. Its basically an "attach antenna and turn on" device.? Going to a tracker only mode is a way to save the battery if that is going to be their mission for the event.? And easy to change if their mission changes.? ? We had one of them "kidnapped" during an event - the organizers loaded it into their truck when an exchange point was closed? we thought the truck was going to the next relay point and we would snag it off the truck, but it went "home" with them.? About 50 miles away.? :)? ?It was doing a bang up job from the inside of a UHaul for the next 18 hours or so.? :)? ?It was hitting an Igate in that city so we knew when the last beacon happened.? They brought it back to use a few days later - but that was an unexpected test of the unit and how long it lasted on its 7ah gel cell.? ?
Being able to change from tracker/digi to tracker only has not presented any problems.? ?
Mary N?TRK
Western Division SATERN Coordinator
Mary,
You can switch between banks in the MTT4BT just as in the regular TT4. This is accomplished by connecting a SPST switch between PA-3 and ground. You have to set BNKMODE to 1 in the configuration to allow the switch to be noticed. One other very easy way to switch between banks is to use a Byonics Display-PS/2 adapter. By using the F5 feature, you can change a lot ( Not all) of the configuration parameters using the display and PS/2 keyboard. You can also send and receive basic APRS messages without having to use a PC, which is very handy.?
I have a question though: Are you (In some cases) trying to A) Stop digipeating while tracking, or B) Stop Tracking while Digipeating? If so, why? If you use SmartBeaconing, you can nearly eliminate any position reports from being transmitted when you are operating as a stationary digipeater, but still send enough position reports when traveling to accomplish your mission. I suggest this route since you won't have to remember to throw a manual switch every time you change applications. Do you have so many units that having your mobiles act as digi/trackers hogs too much bandwidth on your frequency? If you plan to use a unit as dedicated digipeaters, you can also just not connect the GPS to inhibit tracking.
73,
Allen AF6OF
-----Original Message-----
From: Mary Joseph < mljoseph123@...>
To: [email protected]
Sent: Sat, Jul 3, 2021 9:39 pm
Subject: Re: [TinyTrak] Simple Digipeater
I am going to revive this conversation -? ?I would love to be able to install a switch on my MTT4BT so that we could choose tracker or tracker/digi.? ? ?
Since these units are not technically mine (they belong to the Salvation Army) I just don't want to "mess up" the works... replacing the $80 TT4 for my club wasn't as big a deal as at MTT4B -
But I am looking to make using the trackers as simple as possible... but having the ability to change missions with a switch (like I did on my TT4s) would be great.??
So, I know the theory is that it should work... but... has anyone done it??
Mary N?TRK
?
|
Mary,
You can switch between banks in the MTT4BT just as in the regular TT4. This is accomplished by connecting a SPST switch between PA-3 and ground. You have to set BNKMODE to 1 in the configuration to allow the switch to be noticed. One other very easy way to switch between banks is to use a Byonics Display-PS/2 adapter. By using the F5 feature, you can change a lot ( Not all) of the configuration parameters using the display and PS/2 keyboard. You can also send and receive basic APRS messages without having to use a PC, which is very handy.?
I have a question though: Are you (In some cases) trying to A) Stop digipeating while tracking, or B) Stop Tracking while Digipeating? If so, why? If you use SmartBeaconing, you can nearly eliminate any position reports from being transmitted when you are operating as a stationary digipeater, but still send enough position reports when traveling to accomplish your mission. I suggest this route since you won't have to remember to throw a manual switch every time you change applications. Do you have so many units that having your mobiles act as digi/trackers hogs too much bandwidth on your frequency? If you plan to use a unit as dedicated digipeaters, you can also just not connect the GPS to inhibit tracking.
73,
Allen AF6OF
-----Original Message-----
From: Mary Joseph <mljoseph123@...>
To: [email protected]
Sent: Sat, Jul 3, 2021 9:39 pm
Subject: Re: [TinyTrak] Simple Digipeater
I am going to revive this conversation -? ?I would love to be able to install a switch on my MTT4BT so that we could choose tracker or tracker/digi.? ? ?
Since these units are not technically mine (they belong to the Salvation Army) I just don't want to "mess up" the works... replacing the $80 TT4 for my club wasn't as big a deal as at MTT4B -
But I am looking to make using the trackers as simple as possible... but having the ability to change missions with a switch (like I did on my TT4s) would be great.??
So, I know the theory is that it should work... but... has anyone done it??
Mary N?TRK
?
|
I am going to revive this conversation -? ?I would love to be able to install a switch on my MTT4BT so that we could choose tracker or tracker/digi.? ? ?
Since these units are not technically mine (they belong to the Salvation Army) I just don't want to "mess up" the works... replacing the $80 TT4 for my club wasn't as big a deal as at MTT4B -
But I am looking to make using the trackers as simple as possible... but having the ability to change missions with a switch (like I did on my TT4s) would be great.??
So, I know the theory is that it should work... but... has anyone done it??
Mary N?TRK
?
|
Re: MTT4BT and Garmin Montana APRS
Just put my order in:
1 MTT4BT
1 USB-2.5 Cable
1 V3 Antenna
Should get me started.?
|
Re: Negative temperature in Celcius
Wow, what are all those boards in your picture?
As for the negative numbers, that would be a question for Byon.
Going back through the aprs.fi data, the lowest temperature I saw was 30F, which showed as 0C. In theory, this could be resolution and round off error.? I didn't see any temperatures below 30, which would be 'even more negative'.
Do the telemetry parameters match your current telemetry output? Aprs.fi shows your telemetry data as: ?? Power Supply???????? PA
?? Solar Panel P.1?????? SP1
?? Solar Panel P.2?????? SP2
? Battery 1????????????????? B1
? Battery 2????????????????? B2
aprs.fi data with path elements removed???????????????????? PA, SP1,SP2,B1,B2 ,digital
2021-06-29 21:34:13 EDT: >APTT4:T#059,124,000,000,128,127,00000000
2021-06-29 21:38:06 EDT: >APTT4!2529.15S/04913.13WrWX?Davis,FTM100DR,5W,GP6,Ext.Temp.:3C,37F,DGP=OFF
2021-06-29 21:38:30 EDT: >APTT4@.../04913.13W_079/009g015t040r000p018P004h70b10207.DsVP
Just as an experiment, you can try the following settings for telemetry: ??? TELREAD FALSE???????? This will send raw bit values from Analog to digital converter ??? TELHIRES TRUE ? ????? This will? scale the voltage to 0 - 5V will be 0 to 999 counts
??? TELVOLT TRUE??????????? PA will remain TT4 input voltage
??? TELTEMP TRUE?????????? SP1 will be the raw bit value for the temperature sensor ????????????????????????????????????????? The other values will shift right and you will no longer read B2
The millivolt reading is in deg K (x10). So if the analog to digital converter reads about 500, that will be about 2.5V (2500mV)
? to equate to 250 K or (250 - 273.15)? = -23.15 C. Taking a step closer to your value:? 539 / 999 * 5 = 2702? or 270.2 K ?? 270.2 - 273.15 => -2.88 C
Then you could verify the output of the status message vs the telemetry data and see if it really is negative, or just rounding off poorly.
On Tuesday, June 29, 2021, 8:05:52 PM EDT, py5lf_ <py5lf@...> wrote:
<Snip> Robert LM335DZ encapsulated?to put outside ...
Robert This temperature comes from the LM335DZ put outside my shack , using a shielded cable . Also I have a Davis Vantage Vue connected to this TT4. But the main point is this ; TT4 doesn't?show a negative value on Celsius . After reaching zero , the value stays the same , while the temperature in Fahrenheit still works correctly. t^and T^ come from LM335.?
Em ter., 29 de jun. de 2021 às 15:20, Rob Giuliano via <kb8rco= [email protected]> escreveu: Are you sending the temperature from a Davis Weather Station, the Temp sensor on the TT4, or a Temp sensor on a different TT4 analog input?? (assume not the last as it wouldn't be converted to degrees inside the TT4)
On Tuesday, June 29, 2021, 9:44:18 AM EDT, py5lf_ < py5lf@...> wrote:
Friends As you can see TT4 cant send temperatures below zero in Celsius; 2021-06-29 06:29:04 -03:?>APTT4,WIDE1-1,WIDE2-1,qAR,:WX?Davis,FTM100DR,5W,GP6,Ext.Temp.:0C,30F,DGP=OFF? 30F = -1C Any solution ? --
--
|
Re: Negative temperature in Celcius
 Robert LM335DZ encapsulated?to put outside ...
Robert This temperature comes from the LM335DZ put outside my shack , using a shielded cable . Also I have a Davis Vantage Vue connected to this TT4. But the main point is this ; TT4 doesn't?show a negative value on Celsius . After reaching zero , the value stays the same , while the temperature in Fahrenheit still works correctly. t^and T^ come from LM335.?
Em ter., 29 de jun. de 2021 às 15:20, Rob Giuliano via <kb8rco= [email protected]> escreveu: Are you sending the temperature from a Davis Weather Station, the Temp sensor on the TT4, or a Temp sensor on a different TT4 analog input?? (assume not the last as it wouldn't be converted to degrees inside the TT4)
On Tuesday, June 29, 2021, 9:44:18 AM EDT, py5lf_ < py5lf@...> wrote:
Friends As you can see TT4 cant send temperatures below zero in Celsius; 2021-06-29 06:29:04 -03:?>APTT4,WIDE1-1,WIDE2-1,qAR,:WX?Davis,FTM100DR,5W,GP6,Ext.Temp.:0C,30F,DGP=OFF? 30F = -1C Any solution ? --
--
|
Re: Negative temperature in Celcius
Robert This temperature comes from the LM335DZ put outside my shack , using a shielded cable . Also I have a Davis Vantage Vue connected to this TT4. But the main point is this ; TT4 doesn't?show a negative value on Celsius . After reaching zero , the value stays the same , while the temperature in Fahrenheit still works correctly. t^and T^ come from LM335.? Em ter., 29 de jun. de 2021 às 15:20, Rob Giuliano via <kb8rco= [email protected]> escreveu:
Are you sending the temperature from a Davis Weather Station, the Temp sensor on the TT4, or a Temp sensor on a different TT4 analog input?? (assume not the last as it wouldn't be converted to degrees inside the TT4)
On Tuesday, June 29, 2021, 9:44:18 AM EDT, py5lf_ < py5lf@...> wrote:
Friends As you can see TT4 cant send temperatures below zero in Celsius; 2021-06-29 06:29:04 -03:?>APTT4,WIDE1-1,WIDE2-1,qAR,:WX?Davis,FTM100DR,5W,GP6,Ext.Temp.:0C,30F,DGP=OFF? 30F = -1C Any solution ? --
|
Re: Negative temperature in Celcius
Just setup my TT4 to send Telemetry and BText in a similar fashion. My looks like this: ?? KB8RCO-9>APTT4,WIDE1-1,WIDE2-1:>TT4 Alpha 0.72 Bank 1 Temp 35C,95F Bat 13.7V
?? KB8RCO-9>APTT4,WIDE1-1,WIDE2-1:T#000,138,095,999,698,553,00000000
NOTE: 1. This is not being transmitted, so this data will not show on aprs.fi 2. DMetric is false, so I am reporting in Degrees F for telementry data.
Changed DMETRIC TRUE:
?? KB8RCO-9>APTT4,WIDE1-1,WIDE2-1:>TT4 Alpha 0.72 Bank 1 Temp 35C,95F Bat 13.8V
?? KB8RCO-9>APTT4,WIDE1-1,WIDE2-1:T#000,137,035,999,697,552,00000000So, I don't see a mismatch between telemetry data and BText data. Of course, I can't be sure Luciano had TelTemp True
Next test - Change TTEMPTWK 115 (from 128) and TVOLTTWK 110 (from 128)
?? KB8RCO-9>APTT4,WIDE1-1,WIDE2-1:>TT4 Alpha 0.72 Bank 1 Temp 35C,96F Bat 13.7V
?? KB8RCO-9>APTT4,WIDE1-1,WIDE2-1:T#000,137,035,999,698,554,00000000
The values still matched.
I can't explain the difference, other than it may not be temperature.
On Tuesday, June 29, 2021, 3:43:39 PM EDT, Rob Giuliano via groups.io <kb8rco@...> wrote:
I would have guessed that the message format indicates this was a status message, and not a WX message from the Davis Station.
The Telemetry data will send the data according to
If I look on aprs.fi, I see 3 messages of different types:
1. This is the telemetry format:
2021-06-29 12:56:32 EDT: >APTT4,,WIDE1*,WIDE2-1,qAR,:T#271,138,211,208,141,140,00000000
?? This looks like TELREAD is TRUE and TELVOLT is TRUE (first telemetry element is 138 for 13.8V) ???? If TELTEMP is TRUE, t he second should be 21.1C (assuming DMETRIC is TRUE)
2. This one looks like what was in the posting and appears to be just a normal status message with
Ext.Temp.:^t, ^T
2021-06-29 12:56:37 EDT: >APTT4,,WIDE1*,WIDE2-1,qAR,:!2529.15S/04913.13WrWX?Davis,FTM100DR,5W,GP6,Ext.Temp.:14C,57F,DGP=OFF
NOTE: Temperature appears to have changed by almost 7 degrees C in 5 seconds?
? Telemetry message says 21.1C and Status message, 5 seconds later says 14C
3. This one looks like it was created from the Davis data:
2021-06-29 12:58:08 EDT: >APTT4,WIDE1-1,WIDE2-1,qAR,:@291659z2529.15S/04913.13W_072/010g022t047r000p040P004h58b10200.DsVP ? I have no idea how to decode the Davis data
??
On Tuesday, June 29, 2021, 2:41:34 PM EDT, vhsproducts via groups.io <vhsproducts@...> wrote:
Looking at his telemetry fields on aprs.fi, all the reports are scaled in Volts, wouldn't this suggest that the Davis unit is reporting the temperature as derived from the Davis instrument???
73,
-----Original Message-----
From: Rob Giuliano via groups.io <kb8rco@...>
To: [email protected] < [email protected]>
Sent: Tue, Jun 29, 2021 11:19 am
Subject: Re: [TinyTrak] Negative temperature in Celcius
Are you sending the temperature from a Davis Weather Station, the Temp sensor on the TT4, or a Temp sensor on a different TT4 analog input?? (assume not the last as it wouldn't be converted to degrees inside the TT4)
On Tuesday, June 29, 2021, 9:44:18 AM EDT, py5lf_ <py5lf@...> wrote:
Friends
As you can see TT4 cant send temperatures below zero in Celsius;
2021-06-29 06:29:04 -03:?>APTT4,WIDE1-1,WIDE2-1,qAR,:WX?Davis,FTM100DR,5W,GP6,Ext.Temp.:0C,30F,DGP=OFF?
30F = -1C
Any solution ?
--
|
Re: Negative temperature in Celcius
I would have guessed that the message format indicates this was a status message, and not a WX message from the Davis Station.
The Telemetry data will send the data according to
If I look on aprs.fi, I see 3 messages of different types:
1. This is the telemetry format:
2021-06-29 12:56:32 EDT: >APTT4,,WIDE1*,WIDE2-1,qAR,:T#271,138,211,208,141,140,00000000
?? This looks like TELREAD is TRUE and TELVOLT is TRUE (first telemetry element is 138 for 13.8V) ???? If TELTEMP is TRUE, t he second should be 21.1C (assuming DMETRIC is TRUE)
2. This one looks like what was in the posting and appears to be just a normal status message with
Ext.Temp.:^t, ^T
2021-06-29 12:56:37 EDT: >APTT4,,WIDE1*,WIDE2-1,qAR,:!2529.15S/04913.13WrWX?Davis,FTM100DR,5W,GP6,Ext.Temp.:14C,57F,DGP=OFF
NOTE: Temperature appears to have changed by almost 7 degrees C in 5 seconds?
? Telemetry message says 21.1C and Status message, 5 seconds later says 14C
3. This one looks like it was created from the Davis data:
2021-06-29 12:58:08 EDT: >APTT4,WIDE1-1,WIDE2-1,qAR,:@291659z2529.15S/04913.13W_072/010g022t047r000p040P004h58b10200.DsVP ? I have no idea how to decode the Davis data
??
On Tuesday, June 29, 2021, 2:41:34 PM EDT, vhsproducts via groups.io <vhsproducts@...> wrote:
Looking at his telemetry fields on aprs.fi, all the reports are scaled in Volts, wouldn't this suggest that the Davis unit is reporting the temperature as derived from the Davis instrument???
73,
-----Original Message-----
From: Rob Giuliano via groups.io <kb8rco@...>
To: [email protected] < [email protected]>
Sent: Tue, Jun 29, 2021 11:19 am
Subject: Re: [TinyTrak] Negative temperature in Celcius
Are you sending the temperature from a Davis Weather Station, the Temp sensor on the TT4, or a Temp sensor on a different TT4 analog input?? (assume not the last as it wouldn't be converted to degrees inside the TT4)
On Tuesday, June 29, 2021, 9:44:18 AM EDT, py5lf_ <py5lf@...> wrote:
Friends
As you can see TT4 cant send temperatures below zero in Celsius;
2021-06-29 06:29:04 -03:?>APTT4,WIDE1-1,WIDE2-1,qAR,:WX?Davis,FTM100DR,5W,GP6,Ext.Temp.:0C,30F,DGP=OFF?
30F = -1C
Any solution ?
--
|
Re: Negative temperature in Celcius
Looking at his telemetry fields on aprs.fi, all the reports are scaled in Volts, wouldn't this suggest that the Davis unit is reporting the temperature as derived from the Davis instrument???
73,
-----Original Message-----
From: Rob Giuliano via groups.io <kb8rco@...>
To: [email protected] < [email protected]>
Sent: Tue, Jun 29, 2021 11:19 am
Subject: Re: [TinyTrak] Negative temperature in Celcius
Are you sending the temperature from a Davis Weather Station, the Temp sensor on the TT4, or a Temp sensor on a different TT4 analog input?? (assume not the last as it wouldn't be converted to degrees inside the TT4)
On Tuesday, June 29, 2021, 9:44:18 AM EDT, py5lf_ <py5lf@...> wrote:
Friends
As you can see TT4 cant send temperatures below zero in Celsius;
2021-06-29 06:29:04 -03:?>APTT4,WIDE1-1,WIDE2-1,qAR,:WX?Davis,FTM100DR,5W,GP6,Ext.Temp.:0C,30F,DGP=OFF?
30F = -1C
Any solution ?
--
|
Re: Negative temperature in Celcius
Are you sending the temperature from a Davis Weather Station, the Temp sensor on the TT4, or a Temp sensor on a different TT4 analog input?? (assume not the last as it wouldn't be converted to degrees inside the TT4)
On Tuesday, June 29, 2021, 9:44:18 AM EDT, py5lf_ <py5lf@...> wrote:
Friends As you can see TT4 cant send temperatures below zero in Celsius; 2021-06-29 06:29:04 -03:?>APTT4,WIDE1-1,WIDE2-1,qAR,:WX?Davis,FTM100DR,5W,GP6,Ext.Temp.:0C,30F,DGP=OFF? 30F = -1C Any solution ? --
|
Negative temperature in Celcius
Friends As you can see TT4 cant send temperatures below zero in Celsius; 2021-06-29 06:29:04 -03:?>APTT4,WIDE1-1,WIDE2-1,qAR,:WX?Davis,FTM100DR,5W,GP6,Ext.Temp.:0C,30F,DGP=OFF? 30F = -1C Any solution ? --
|
Re: MTT4BT and Garmin Montana APRS
Compton,
Certainly. When the MTT4BT or even more so, the MTT4BT-40 (40 Watt MTT4BT transceiver) have a high SWR during transmission, the processor may become "Swamped" with RF voltage building up on the board, and the TT4 loses control.? You will typically see the two bi-Color LEDs continuously flash, as if the four individual LED's are showing the same pattern as they do on immediate powering of the unit. This is typically what the lower power (10) Watt unit will do when the antenna has a very poor match, and is generally harmless. It may potentially toast the final amplifier, and/or result in corrupt firmware, but this can be reloaded by the end-user or by us ( Byonics) You may hear the T/R relay clicking while this is happening.?
?When the high power MTT4BT-40 goes into continuous reset, the device may lock up in the transmit-mode. Nothing but a carrier will be transmitted, and if this goes on too long, the final amplifier, and even the PCB and case can melt. That's the expensive smoke.??The units that have been melted into hideous globs of stinky plastic have usually been caused by things like people removing their antennas before entering car washes and forgetting to turn of the MTT4BT-40's power when disconnecting the antenna. Note that the RF output from either the low power unit ( up to 14 Watts) or the High power unit ( Up to 40 Watts) can cause RF burns and tattooing. ( Important safety tip!)?
Other issues are crappy coax and bad antennas, coax pinched or strangled in car door frames, etc. This is also a problem we have seen in our MT-RTG-50 ( 50 Watt Transmit-only device? that can actually have as much as 90 Watts output, depending upon power supply voltage and impedance) The little "Hershey's kiss" antenna that we provide for free with our low power RTG transmitter is a great example of an awful antenna for the MTT4BT. RG-174u coax, questionable SWR, and low magnet mass are not good things for a higher power transmitter.
The Mass of an MTT4BT transceiver is less than 4 ounces. Imagine putting a rubber duck antenna on a 40 Watt handheld transceiver! It would be bad. The MTT4BT transceivers?were designed for mobile APRS, which means a fairly low duty cycle, and relying on the Mass of an automobile to act as a counterpoise "Ground" for the transceiver. Consider this as if you were a person floating in space, trying to throw a heavy weight,?Isaac?Newton conspires against your putting very much force into the throw. ( This is not a perfect analogy, so physics?people don't go postal on me) As a practical matter, this effectively means as we increase the output power of a transmitter, we need to increase it's Mass for two reasons. One, we need a heat sink that can handle the wasted power, On the MTT4BT this is the PCB itself; there is no other heat sink, but since APRS duty cycles are very low, the PCB is enough. The second reason is that we need enough Mass in the transmitter?to act as a counterpoise to the antennae. That Mass must increase directly to handle the poorer antennas. The MTT4BT's are happiest with a mobile antenna, like an NMO or big magnet mount.?
For the last few months,? all the stocked? MTT4BT-40's and RTG-50 Transmitters ( And a few rare RTG-100 Watt transmitters) have had thermostatic switches added to the power amplifiers. If the amp gets hotter than 50 C, it gets turned off until the unit cools down substantially below that. This should prevent expensive smoke from leaking out of the units if they get locked on. (BTW, if anyone wants to have me add the thermal circuit breaker to their older MTT4BT-40 or RTG-50, I will do so for the cost of return shipping- I understand that return shipping to Australia is a horribly expensive thing, so I will be producing a set of instructions on how to add one yourself if you are so inclined)?
It was suggest in one of the recent posts to use an antenna that does not require a substantial ground plane. We have found that our V6 antenna ( A center-fed, half-wave dipole) works quite well with the MTT4BT-40, although it would not work well on a motorcycle. a 5/8ths wave antenna might also be a good choice.
73,
Allen AF6OF
-----Original Message-----
From: Compton <comptonallen@...>
To: [email protected]
Sent: Sun, Jun 27, 2021 8:15 pm
Subject: Re: [TinyTrak] MTT4BT and Garmin Montana APRS
Hi Allen,
Are you able to describe the symptoms of continuous reset you note?
?
--
Compton
VK2HRX
Sydney, Australia
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Re: MTT4BT and Garmin Montana APRS
Hi Allen,
Are you able to describe the symptoms of continuous reset you note?
?
--
Compton
VK2HRX
Sydney, Australia
|
Re: MTT4BT and Garmin Montana APRS
Use a ground independant mobile antenna. This means you can mount it anywhere you like. I don't know what is available on your side of the world, so I can't recommend one.
Also ground independant mobile antennas make great home base antennas, as you can mount them on top of a pole and they work beautifully. I run a small pigtail lead of RG58 and then step it up to RG213 to reduce the losses over the run.
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Show quoted text
Final question before I put in my order- What antennas are appropriate for an ATV/Motorcycle (not much metal). Will a HT
Nagoya NA-771whip be appropriate?
|
Re: MTT4BT and Garmin Montana APRS
Probably the best solution is a simple 1/4 wave verticle.? Since the 1/4 wave on 2 meters is only about 20 inches, you can probably find a way / place to mount one 1/4 wave (driven) element vertically and one or two horizontal (or slightly sloped) in a way that fits a motorcycle.
I've seen these types of antennas on short poles so that they are just above anyone on the motorcycle seat.? You will need to get a little creative.
On Sunday, June 27, 2021, 7:22:03 PM EDT, vhsproducts via groups.io <vhsproducts@...> wrote:
The MTT4BT will not work with a rubber duck antenna. You need a mobile-style mount and whip to load it properly. Excessive SWR will cause the unit to go into continuous reset. Rubber duck whips are in general, the work of the devil. Motorcycle antennas are always a challenge, but I have seen good results with mobile mounts ( NMO, etc) mounted to the chassis or license frame brackets. I am sorry that I don't have an easy turn-key solution for bikes.?
73,
Allen AF6OF
-----Original Message-----
From: toy4trax@...
To: [email protected]
Sent: Sun, Jun 27, 2021 3:18 pm
Subject: Re: [TinyTrak] MTT4BT and Garmin Montana APRS
Final question before I put in my order- What antennas are appropriate for an ATV/Motorcycle (not much metal). Will a HT Nagoya NA-771whip be appropriate?
|
Re: MTT4BT and Garmin Montana APRS
The MTT4BT will not work with a rubber duck antenna. You need a mobile-style mount and whip to load it properly. Excessive SWR will cause the unit to go into continuous reset. Rubber duck whips are in general, the work of the devil. Motorcycle antennas are always a challenge, but I have seen good results with mobile mounts ( NMO, etc) mounted to the chassis or license frame brackets. I am sorry that I don't have an easy turn-key solution for bikes.?
73,
Allen AF6OF
-----Original Message-----
From: toy4trax@...
To: [email protected]
Sent: Sun, Jun 27, 2021 3:18 pm
Subject: Re: [TinyTrak] MTT4BT and Garmin Montana APRS
Final question before I put in my order- What antennas are appropriate for an ATV/Motorcycle (not much metal). Will a HT Nagoya NA-771whip be appropriate?
|
Mary Joseph
Compton
Doug J