JumboSpot with intermittent transmission

MMDVM_HS Hat hardware
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k8md
Posts: 4
Joined: Wed May 08, 2019 2:04 am

JumboSpot with intermittent transmission

Post by k8md » Wed May 08, 2019 5:03 pm

I have a v1.7 jumboSpot from a Chinese seller via eBay on top of a RPi zero W. I went through MMDVMcal to calibrate transmit levels using the F5UII method by pushing the Bessel level (j0) to minimum. I verified that transmit is on frequency (< 20 Hz frequency error). I verified that it's generating ~15mw power.

In spite of this, I'm getting intermittent transmit from the JumboSpot. I'm using a cs750 to receive. The cs750 will receive approximately 1 sec of audio from the jumboSpot, then stop decoding. Sometimes I only receive the first 1 sec of audio and nothing else from a 12 sec transmission. Other times receive will go in and out, at an uneven period. Approximately 1 sec of audio, 2 sec of silence, 1 sec of audio, 3 sec of silence, etc.

During the entire duration of a transmission, the jumboSpot is on frequency, and modulation and power are both consistent (~2.8 khz FM deviation, 15mw power).

I'm using a HP8920A to make freq, deviation, and power measurements.

Any ideas?

k8md
Posts: 4
Joined: Wed May 08, 2019 2:04 am

Re: JumboSpot with intermittent transmission

Post by k8md » Wed May 08, 2019 5:04 pm

I should add, I tried flipping TXinvert with no success.

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KE0FHS
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Location: Colorado, USA
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Re: JumboSpot with intermittent transmission

Post by KE0FHS » Wed May 08, 2019 5:23 pm

In DMR Configuration, try turning DMR EmbeddedLCOnly on. Different stations and radios encode and decode Talker Alias data in different ways. One way this variance manifests is that some models of radios can experience audio drop-outs when receiving Talker Alias data from some stations. Apparently, Connect Systems radios can be affected by this.
73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

k8md
Posts: 4
Joined: Wed May 08, 2019 2:04 am

Re: JumboSpot with intermittent transmission

Post by k8md » Wed May 08, 2019 11:51 pm

I appreciate the help, but that did not work.

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