Glib Glob and Squawk

Why do I keep getting those noises and how can I try and fix them?

Firstly, welcome to the wonderful world of Yaesu System Fusion, C4FM, Digital Narrow and Voice Wide. Sometimes we are lucky, we build or buy a digital hotspot and it just works. Sadly that is not always the case and sometimes we need to make some adjustments to make things shiny.

The first thing we need to check is our internet. Ideally, we don’t want a link score of less than 50 / 70. A good solid wifi connection and overall internet are important to prevent dropouts or strange squawking sounds.

I could have had a glib glob free QSO, had it not been for that pesky B.E.R

Next, we need to look at our B.E.R (Bit Error Rate) and adjust the hotspot for the best result. Thankfully pi-star comes with a tool to help us calibrate this value.

Why do I have to do this you may ask? Different hotspots are made using different grades of components. Some oscillators are accurate enough and some are way out. To fix this we have to adjust the RX/TX offsets on the hotspot to match those of our handheld radio.

So on to the tool, We need to use a command line terminal to do this. Thankfully Andy provides you with one built into pi-star. Click on configuration and log in. Now click on ‘Expert’ and then on ‘SSH Access’. This will open a terminal window. Log in using your usual pi-star login details. Next, we want to run the calibration tool.

sudo pistar-mmdvmcal
Type sudo pi-star-mmdvmcal and press enter

Here we have some options. We either need our radio set on the default frequency of 430.000mhz or we can change the frequency to meet that of our radio.

If you press e you can enter the frequency to operate tests on

Now that we are on the same frequency, let’s start up the B.E.R monitor. Chose option shift j. Make sure your handheld is in DN mode for this!

Press j to enter YSF BER Test Mode

Now key up your handheld and watch the numbers going up the screen. In a perfect world, we want these to be 0.0% but anything under 1.0% is considered OK.
While keyyed up, press the f or shift f key repeatedly until your percentage is as low as you can get it.

Press f to go down in frequency and shift f to go up, find the lowest % you can achieve

When you have found the lowest % you can, press q and you will be shown the offset as below

Press q to quit and you will be told the offset you ended up with.

This is showing you what offset you will need to apply to get the best B.E.R. Make a note of it and then move on to the next section.

OK, so now we have an offset, what do I do with it?

Next, we need to set the offset for our RX/TX in pi-star. Click on configuration. Pi star will ask you if you wish to leave the SSH page and say yes. Now click on ‘MMDVMHost’. Scroll down the page and you should come to an option called ‘Modem’. Scroll down a little more until you find RXOffset and TXOffset. You want to put the number we gained at the previous step into both of these boxes. Once done, click ‘Apply Changes’

Other causes of Glib Glob and Squawk

Other things to check are QRM on the frequency of the hotspot. Use FM to listen for any noise or other interference. If you find some, use a different frequency and try again.
As mentioned at the start of this post, make sure the internet/wifi is good and if not, try placing the hotspot somewhere else in the area.
A common mistake is to stand the hotspot close to the router, but some routers don’t like having a transmitter right next to them and can cause issues.

Disclaimer: I am a radio amateur. I am not a qualified commercial communications engineer and the above is based on my own experiences. While I believe the above to be correct, should you find errors, omissions or have some useful input to enhance this post, please contact me using the contact form on this site.