Radio issue...

APADDEN07

Member
Having pretty concerning failure with our HPT404BT. Setup as usual and noticed decreased signal, used this same base setup two weeks in a row and was able to get 2000-3000' over rough terrain in heavy canopy. Was unable to get to my check point (which I've been able to locate regularly) 1400' down the road in wide open sky. Went back to the base, checked the radio, cables, battery antenna, etc. Everything seems fine, just not working properly. Shut everything down and restarted. The T3 base then started to act like it wasn't paired, or at least properly paired with the UHF radio. I turned everything off again (T3 Base, LS+ Rover, and Radio) and restarted using just the 1 watt internal radio on the T3, that seemed to work fine, so I think that means there's something wrong with the external UHF radio. Is there any way to troubleshoot that without the cable used for pairing the base and radio? (I don't have a pairing cable handy)

20210917-14.30.30_00998_Setup_Base.png

20210917-14.21.58_00998_UHF_Status.png
20210917-14.27.01_00998_Spectrum_Analyzer.png
 

Andrey Simonov

Active Member
JAVAD GNSS
We can perform the diagnostic for HPT404BT. Please give us serial number of HPT404BT, we will create RMA and we will send it to you with our shipping address.
 

APADDEN07

Member
Per Matt's suggestion I set everything up in the parking lot and tried again to check the RSSI at 100'. The 4 Watt seems to start up and connect to the base fine, I can scan for clear frequencies, send "to base" etc. When I start the base the radio startup seems to get hung up and then eventually looks like it times out. I checked the lights on the 4 Watt and neither the TX/RX lights are flashing. Unable to check the RSSI values since the radio doesn't start broadcasting.

Changed setups to use the internal 1Watt on the T3. With the following results:
20210922-15.34.27_00998_UHF_Status.png
20210922-15.35.52_00998_UHF_Status.png


According to Matt's slide those values should be -31 [-61] (external) & -43 [-53] (internal).

So, I guess if sending the 4 Watt (HPT404BT S/N:00134) in is the best path forward here that's fine, but now I'm also concerned that the LS+ (S/N: 00998) has an internal issue as well.
 

APADDEN07

Member
Is this something that can be fixed with netview & modem or does it need to be sent in? We're approaching leaf-off season in a hurry and not having a radio is going to really hamper the workflow.
 

Adam

Well-Known Member
5PLS
A JSupport session can be set up for the engineering team to look at the radio and LS. Also, a rental radio is $500 plus shipping. You keep it until you get your radio back from the factory.



 

Vahe Tadevosyan

Member
JAVAD GNSS
Is this something that can be fixed with netview & modem or does it need to be sent in? We're approaching leaf-off season in a hurry and not having a radio is going to really hamper the workflow.
I suggest to create RMA for HPT404 you have.
About LS test in parking lot: the point is that in parking lot you will probably got the effect of multipathing which caused a little bit unusual values of RSSI. In my opinion only HPT404 needs an RMA.
 

APADDEN07

Member
Was able to connect to netview & modem today (finally got the cable in from California), radio and base were still paired correctly, reloaded firmware on both the t3 and hpt404bt, cleared NVRAM on T3. The radio was able to connect to the base at startup, which is an improvement and it does appear to be transmitting, but unable to receive based on the lights. TX lights are flashing steady every second or so, but you can hear an audible electrical screech (think dial up modem) every time the light flashes. Maybe i've just never noticed that before, but that doesn't seem healthy. Also, in the base/rover screen after starting the base, the base ID stays blank even after both radio antennas go to "OK".

Only thing I have left to check is the battery, what exactly am I looking for as far as good vs bad battery readings?
 

APADDEN07

Member
Was able to connect to netview & modem today (finally got the cable in from California), radio and base were still paired correctly, reloaded firmware on both the t3 and hpt404bt, cleared NVRAM on T3. The radio was able to connect to the base at startup, which is an improvement and it does appear to be transmitting, but unable to receive based on the lights. TX lights are flashing steady every second or so, but you can hear an audible electrical screech (think dial up modem) every time the light flashes. Maybe i've just never noticed that before, but that doesn't seem healthy. Also, in the base/rover screen after starting the base, the base ID stays blank even after both radio antennas go to "OK".

Only thing I have left to check is the battery, what exactly am I looking for as far as good vs bad battery readings?
Update, new battery seems to have done the trick. Thanks!

Also, the LS+ was part of the original radio wiring fix and never got sent in, so we're taking care of that through a separate communication.
 

John Thompson

Well-Known Member
When the battery voltage for the external UHF radio runs low, it seems to me like it's difficult to diagnose the problem unless I've seen it before (recently). The lights all look correct, but it doesn't work. I have noticed the screeching sound, but it's pretty faint. For an external radio, the voltage displayed in the UHF screen is blank like in the screenshot in the first post. It would be super helpful if it showed the battery voltage, and even better if it made a warning if the voltage gets too low.
 

Eric Tweet

Active Member
John's comment reminded me to get around to making a post about my solution to low-voltage-related issues. But I do agree, having voltage data for an external radio would be very helpful.

I get the "radio screech" too, but it doesn't appear to have caused any kind of damage in the last 4-5 years of regular use. I only notice it if I'm specifically listening for it up-close. Magnetostriction and piezoelectric-induced noise is not terribly uncommon in certain components operating at high frequencies.
 
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