FM repeater not working, what's going on?

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M0ONP
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Joined: Fri Nov 11, 2022 10:43 pm

FM repeater not working, what's going on?

Post by M0ONP »

Hello,

I'm new to Pi-Star so I'm not sure what I'm doing wrong here. I'm trying to set it up as an FM repeater. I have it running on a Raspberry Pi 4B with a AURSINC MMDVM Duplex Hotspot. I managed to set it up for D-Star so things were working at one point. I press the PTT of my radio on the right frequencies with the right CTCCS frequency, nothing happens, as in, my other radio set up for the same repeater doesn't get anything.

This is how I have it set it up for FM:

Image

Image

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I'm trying to emulate this repeater (which is far enough from where I'm located): https://ukrepeater.net/my_repeater.php?id=2765

AURSINC MMDVM Duplex Hotspot I bought from here: https://smile.amazon.co.uk/gp/product/B ... UTF8&psc=1

Any ideas why it's not working? Or how to debug it? I'm not sure why to try next.
G4FDL
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Re: FM repeater not working, what's going on?

Post by G4FDL »

FM mode is only intended to be used on a repeater with real radios and a controller, not a hat like you have.
M1DNS
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Re: FM repeater not working, what's going on?

Post by M1DNS »

The 7021 rf chips used in hotspots can't "Do" FM... (not, without additional work)

One of the reasons why its only been partially integrated into pi-star.

So as replied above, its use case within MMDVM was primarily intended for repeaters and/ or simplex gateways that use equipment with a 'real' RF deck.

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Andrew M1DNS.
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M0ONP
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Re: FM repeater not working, what's going on?

Post by M0ONP »

Oh, that's unfortunate. So I can have a D-Star repeater with this hat, but not an FM one. Your reply seems to point to this being a hardware limitation, is that the case?

Is there a way to cheaply have a low power repeater at home?
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G8SEZ
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Re: FM repeater not working, what's going on?

Post by G8SEZ »

M0ONP wrote: Sun Nov 20, 2022 7:16 pm Oh, that's unfortunate. So I can have a D-Star repeater with this hat, but not an FM one. Your reply seems to point to this being a hardware limitation, is that the case?
Yes, these HATs were designed for digital modes, not analogue ones. The ADF7021 RF modem chip is not designed nor intended to operate in FM mode. You could have a look at the data sheet to understand why.
Is there a way to cheaply have a low power repeater at home?
If you want that then you could have a look at the Allstar node. Should be plenty of information via Google.
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Brian G8SEZ
AF6VN
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Re: FM repeater not working, what's going on?

Post by AF6VN »

M0ONP wrote: Sun Nov 20, 2022 7:16 pm Oh, that's unfortunate. So I can have a D-Star repeater with this hat, but not an FM one. Your reply seems to point to this being a hardware limitation, is that the case?

Is there a way to cheaply have a low power repeater at home?
Considering most of these units only provide around 10-100mW transmit, and many HTs low-power is around 500mW, trying to do a repeater using a "hat" is rather futile... The HT reaches further than the "hat", making direct simplex the more useful mode.

Also take into account that Pi-Star/MMDVM don't do repeater ID; you'd need a separate controller just to get the ID out periodically. (D-Star embeds call-sign of speaker, but that still wouldn't ID the repeater). For all practical purposes, hotspots appear to operate under FCC Part 15 rules -- incidental radiators, pre-FRS "toy" walkie-talkies, wireless telephone handsets...

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AF6VN
Dennis L Bieber
M0ONP
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Re: FM repeater not working, what's going on?

Post by M0ONP »

AF6VN wrote: Sun Nov 20, 2022 9:36 pm Considering most of these units only provide around 10-100mW transmit, and many HTs low-power is around 500mW, trying to do a repeater using a "hat" is rather futile... The HT reaches further than the "hat", making direct simplex the more useful mode.
For what I want to do, 100mW of power is enough. What I want to do is play with and learn about various repeater configurations.
M0ONP
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Re: FM repeater not working, what's going on?

Post by M0ONP »

G8SEZ wrote: Sun Nov 20, 2022 8:31 pm If you want that then you could have a look at the Allstar node. Should be plenty of information via Google.
What is Allstar node?

I searched for it and I found this https://www.allstarlink.org/
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G8SEZ
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Re: FM repeater not working, what's going on?

Post by G8SEZ »

M0ONP wrote: Fri Nov 25, 2022 10:22 pm
G8SEZ wrote: Sun Nov 20, 2022 8:31 pm If you want that then you could have a look at the Allstar node. Should be plenty of information via Google.
What is Allstar node?

I searched for it and I found this https://www.allstarlink.org/
Looks about right, you might find information on pre-built nodes by searching for G7RPG as well.
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Brian G8SEZ
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