forum.pistar.uk

I bought a jumbo spot / mmdvm hat from ebay and I am having issues with it. It has an oled screen on it. I setup pistar for dstar and connected to ref 030c. I set pistar to use 438.9 for rx and tx. When the dashboard shows a call from the reflector ( I also hear audio from my local repeater on my radio) no RF comes out the board. I have watched it with my SDR and radio tuned to the frequency. During that call the oled screen also shows d-star and the call info. If I transmit on that frequency from my radio it never shows as local RF. I figured if it was an offset issue I would see the RF on my SDR. In the 1 mhz slice centered on 438.9 I am watching I see noting.

Its acting like the rx/tx chip on the board is dead. I have tried all the radio/modem types that say GPIO thinking my china clone board might like a different modem better. Same results.

I am running Pi-Star:3.4.13. I also tried the hat on a pi2 and a pi3 same results.

Am I missing something? I also did the firmware update to HA_Hat 1.3.7 and still nothing.

Hi KG5SKI, I too have the same problem with a jumbospot. Have you found a solution?

The 2018 boards are experiencing a lot of DOA. Sorry to say.

Sent from my SM-G950U using Tapatalk

Hi,
I had the same problem - no TX or RX from the Jumbo Spot board. I checked the output from the 14.7456MHz TCXO which is the reference oscillator for the ADF7021 TX/RX IC and it was dead - no RF output. Rather than return it to China I replaced the TCXO with a FOX924B-14.7456 MHz TCXO. Cost me GBP 2.75 from Farnell:

http://uk.farnell.com/fox-electronics/f ... f-00001000.

All working OK now.

73, Dave G3XOU

Hi all,
More JumboSpot issues. I checked the RF output power on my JumboSpot (2018 batch) from the SMA connector. It was well down on spec at -30dBm. I checked the RF output from the ADF7021 (pin 4) and it was +13dBm. It looks like they've fitted the wrong value parts in the low pass filter as there is over 40dB loss between the ADF7021 RF output and the Antenna. I have checked all the inductors for continuity and they are all OK and there is no short across the SMA connector. Can anyone else confirm what RF output they have from a 2018 batch JumboSpot.

73,
Dave G3XOU

Would the TCXO show up on my dashboard if was no good

KD1UA wrote: ↑Sun Dec 30, 2018 5:33 pm Would the TCXO show up on my dashboard if was no good

I would think a bad TXCO wouldn't show up at all due to it not being measurable.

The TCXO frequency is pulled out of the firmware version I believe, if the ADF7021 has no clock then you get no TX or Rx activity.

If the STM32 clock is not running then the firmware doesn't initialise. You can normally spot these problems using live log output in a separate browser tab and read between the lines of the messages seen during and after boot.