Walkie Talkie Static and Interference

[Lawrence_Chehimi]

I was recently looking into installing a CB unit in my patrol and hide it inside the center console with a rj45 socket as per the below. But can't find a unit that has a display in mic/speaker that works with the frequencies we use. 

[GauravSoni]

19 minutes ago, Gaurav said:

Buy Kangda - 300 dhs or use mine in your Pajero to test and then decide.

Thanks @Gaurav will surely try next time we drive!

[Gaurav]

@Lawrence_Chehimi I used CB radio (462 range) and they are pain as they are fixed unit and you cant step out with radio.

We are using licensing free frequency (446 range), maybe that's why those CB units doesn't cover that range.

[Lawrence_Chehimi]

I recently started using the below unit, i'm also not facing any kind of interference, but seems it doesn't transmit or receive over much distance with the short antenna. It is a bit bulky in hand, the other antenna that came with it is also inconvenient to use in the car.

[Frederic]

6 minutes ago, Lawrence_Chehimi said:

I recently started using the below unit, i'm also not facing any kind of interference, but seems it doesn't transmit or receive over much distance with the short antenna. It is a bit bulky in hand, the other antenna that came with it is also inconvenient to use in the car.

This is a good radio and definitely a good step up from the Baofeng radios. The short antenna will be more than suitable to transmit within convoy distance (further than that should be avoided anyways). 

[Zed]

23 hours ago, Frederic said:

To reduce interference, there is a setting called "SQL" on your radio which sets the "sensitivity" to which the radio will open its channel. The higher the setting the less sensitive it becomes, so you can experiment with this. It works a bit like an aperture setting on your camera lens

On the Baofeng UV5R, which is a great radio especially for that price, this model is known to be a bit more sensitive, and a hack was created a few years back to change the SQL limit from 9 into a much higher level. This involves using the Baofeng USB cable (which you can find on Amazon) and the free software called "CHIRP".

Dear Prof. @Frederic, SQUELCH (SQL setting) is the White Noise ("ssszzzzz"). Setting SQL to high basically mutes white noise, that may be caused by other radio signals, mobile phones, or even electronics from our cars, BUT high SQL means now your radio will only receive the STRONGEST signals from other radios on the same frequency. If you are in the same building yes, high SQL makes sense, but when we are 10-cars apart, a high SQL can mean you only hear the car in front of you and behind you. Of course this needs testing, but this is the theory anyways 😁

I propose 2 different approach (again needs testing, but we engineers like to test assumptions, right? 😀)

1. Set SQL to be as low as possible instead of high. The default is 5 on Motorola and probably most other radios. We can try 3 and see if white noise is audible or not. The reason is when we set SQL LOW, we allow "weaker signals" to come to us... weaker signals as in the Marshal in front who is 9 cars ahead.

This is also called Noise Squelch: muting background noise.

2. Make use of CTCSS code. This is like a "password". So yes we are using license-free Channel #1 446.00625 MHz and there are 2 clubs using this channel. Group #1 uses Channel 1 + CTCSS code 77  while Group #2 uses Channel 1 without any CTCSS. Now comes another Club, Group #3 with Channel 1 again without any CTCSS. Guess who will hear each other voices? Group #2 and Group #3 will hear each other and may cause confusion unless they switch channel. Meanwhile, Group #1 who is a Smart Group like Carnity is not distracted by Group #2 and Group #3, because they have password-protected their free Channel #1 with the CTCSS code 😉

This is also called User Squelch: muting other Non-Carnity Users, which is what we probably want in our convoy...

Below visually depicts what I mean:

 

 

Edited October 19, 2021 by Zed
added YouTube video on CTCSS

[Frederic]

1. The reason i propose increasing SQL is to disable the radio from picking up signals “outside” the convoy. A 5 Watt radio can easily broadcast and receive signals within our convoy range, except inbetween large dunes but that’s unavoidable.

2. CTSS coding is a good feature, but we have struggled massively in the past to get all people to program their own radios (hence the videos and tutorials). Implementing CTSS codes for every channel will complicate the matter as most people are not familiar with those settings and if set incorrectly they won’t be able to broadcast or receive even though they are on the same frequency. In the early days of the club we were spending more time on programming the radios of new members than actually doing a proper briefing and introduction. Hence I’m not a fan of this option (the KISS method works best) 😀.

I am sure we can keep static and interference well under control by using a good radio that works for you and your car and a bit of SQL fine tuning. As we mentioned we have seen a definite improvement of a 70dhs radio vs a 300dhs radio (as is to be expected).

 

[Zed]

2 minutes ago, Frederic said:

. Hence I’m not a fan of this option (the KISS method works best) 😀.

I am sure we can keep static and interference well under control by using a good radio that works for you and your car and a bit of SQL fine tuning. As we mentioned we have seen a definite improvement of a 70dhs radio vs a 300dhs radio (as is to be expected).

 

Fair enough, Keep It Simple and Noise-Cancelling (more expensive radios) are easier for everyone 😁👍🏻

[Warren Flay]

23 hours ago, Russ said:

I tend to suffer with this @Frederic (I have the Baofeng). For me sometimes a simple fix is moving the radio away from the vicinity of the centre console as it is often worse there. 
Thanks for the hack on the SQL limit! 

Same for me! In the centre console it gives static, I lift it up and it stops.

[Varun Mehndiratta]

On 10/18/2021 at 8:33 AM, Frederic said:

During the drive you might face static, noise, or interference on your walkie talkie. There are many possible reasons for that. I will list them as per most likely:

1) Our Frequency range is License-Free, hence it can be used by anyone. In busy areas or high altitude this can be an issue.

2) Our radios are not professional grade, and more prone to interference compared to the branded expensive ones (which need a license to buy). We see good results from the Crony/Motorola MT777 and the Kangda branded radios. The Baofengs are ok but seems to be more sensitive.

3) Your vehicle. Yes that's right, we have seen cases in which there is constant interference while sitting inside the vehicle, and this stops when exiting the vehicle. There is lots of electronics in the car which can cause this. 

 

To reduce interference, there is a setting called "SQL" on your radio which sets the "sensitivity" to which the radio will open its channel. The higher the setting the less sensitive it becomes, so you can experiment with this. It works a bit like an aperture setting on your camera lens

On the Baofeng UV5R, which is a great radio especially for that price, this model is known to be a bit more sensitive, and a hack was created a few years back to change the SQL limit from 9 into a much higher level. This involves using the Baofeng USB cable (which you can find on Amazon) and the free software called "CHIRP".

Below a description on how it works:

https://www.miklor.com/COM/UV_Squelch.php

Baofeng USB Programming Cable for Baofeng UV-5R,BF-F8HP, BF-888S,UV82HP,UV-9S,UV-R3 Handheld ham Radio transceiver Ham Two Way Radio with Driver CD: Buy Online at Best Price in UAE - Amazon.ae

Download - CHIRP (danplanet.com)

 

Thanks @Frederici had this issue for a while with my Baofeng radio - my first drive with you last month, couple of seconds with radio in maestro's hand and as @Srikumar said Abracadabra it's fixed...SQL setting did the trick.