Radio for Jabiru

[Keith W]

In my j230 I have a Filser ATR 500 radio, I have been given another one the same but I need someone to make me a harness with a switch where I can monitor both radios and transmit on the one it is switched to, should I go this way or am I better of to get something like RF Guys radio that monitors multiple channels, thanks Keith.

[RFguy]

You cant really  'cleanly' monitor two radios at once without some electronics, IE if one turns off it will load the other down. You can use a couple of resistors in series with each radio ' combine' - say 100 ohms but there will be quite alot of annoying interaction. try and find an low cost intercom panel.

Should have my radio shipping nend of year, I'm on a promise with a few. 

[Keith W]

I have the standard Jabiru intercom, had the same in my 160 and it worked fine, it had 2 Becker radios would you be able to make me a harness thanks Keith.

[RFguy]

Hi Keith

I'm not familiar with whatever a 'standard jabiru intercom ' is. I didnt think there was one.  Microair built in intercom is what I am used to seeing. 

But to deal with two radios 

1) You need a DPDT (double pole, double throw) switch to switch the PTT and microphone to the radio of interest. just switch active wires, no need to switch the grounds. 

2) for the radio audio output - two resistors in series down to a single wire should be OK, suggest 100 ohm , 1/2W resistors, in series with each output before the join. That will stop them interacting too much. .

 

[Keith W]

Thanks for the advice but to make the harness is a bit beyond my capabilities that’s why I’m chasing somebody to make me one thanks Keith.

[Roscoe]

On 17/11/2023 at 9:54 AM, Keith W said:

Thanks for the advice but to make the harness is a bit beyond my capabilities that’s why I’m chasing somebody to make me one thanks Keith.

May be easier and simpler to buy something like a TRIG Com Radio which you can put in monitor mode and then transmit on either freq when desired.

[RFguy]

there seems to be a market for a  "matrix box", due to the lack of electronics people

 

I forsee a PCB with screw cage connectors for 'anything' that can be configured to hook up 'anything'.  IE connect all the items , just get the grounds in the right place, and that is all.  

 

The labour is the problem. If you can set up the product such that the owner provides the labour in terms of merely connecting wires to the board (and in no particular order), then a high level person remotely can program the board (and if required, have the installed/ owner plug some jumpers in like a checkerboard. said board needs to be able to sample and feed back to the high level person that configures (sets gains, polarities etc of signals) 

 

discuss.

[KRviator]

1 hour ago, RFguy said:

there seems to be a market for a  "matrix box", due to the lack of electronics people

 

I forsee a PCB with screw cage connectors for 'anything' that can be configured to hook up 'anything'.  IE connect all the items , just get the grounds in the right place, and that is all.  

 

The labour is the problem. If you can set up the product such that the owner provides the labour in terms of merely connecting wires to the board (and in no particular order), then a high level person remotely can program the board (and if required, have the installed/ owner plug some jumpers in like a checkerboard. said board needs to be able to sample and feed back to the high level person that configures (sets gains, polarities etc of signals) 

 

discuss.

Jim Weir of Kitplanes fame did an article maaaaaaaaannnnnnnnnnnnyyyyyyyyy moons ago about DIY'ing your own audio panel, with any number of inputs you wanted. Damned if I can find it, but it was online as a PDF for eons, and it wouldn't take too much to import that into one of the PCB manufaturers online websites and have them spit out your very own PCB audio panel.

I use JLC PCB for my prototypes and they've been reasonably priced and have a quick turnaround.

I'll keep digging for the Kitplanes PDF in the meantime.

[FlyBoy1960]

Now thats a name i havent heard for around 20 years, is he still with us ?

[KRviator]

Best I can tell he is. And to top it off, he's revised his audio panel design as recently as 2022.

Here's his 2022 article.
Here's the link to his 2002 DIY audio panel one. And you'll need THIS PDF of the schematic too. Reading the article, it looks to be a multi-part series, but I cannot find the other sections. I think I still have some hardcopy KP magazines that far back, so if anyone wants to delve a little deeper into actually doing it, I can go have a look-see to find out if I have P2 / P3.

[RFguy]

the 'universal board' could be done these days with lots of available integration IE its not a intercom or radio or anything, IE the inputs and outputs are universal, audio and all. 

it's just a matrix connections to get all the audios the right level, split combined or whatever, all the PTTs etc routed etc etc aux audio mixed in etc . because of the difference in impedances etc, it's hard to have just a board with amplifiers and pots. 

leaving someone purely to connect the wires, and config done over a wifi  connection (from a hotspotting phone)  to the net.