Noise toy box design questions

[Cutlass327]

I am assembling a box, was originally meant to just be a splitter for one mic to go to 2 radios, but since have added it as a place for noise toys too.

A brief description of box. On top are mic outputs to the radios. 2 short (about 1' long) cables of shielded mic cable from the top to each radio. The front 2 jacks are the "inputs". Basically, it is just 4 four pin mic jacks tied together inside. The audio pins are connected with coax wire, the RX and TX pins are connected with regular wire. I connected the modules to the bottom mic jack (audio and tx), and the power/ground are connected to an old 3 pin style CB power jack in the back. The power is connected to the same power source as the radios. Just for kicks, a volt meter on a momentary switch to power plug is in it too. The power to the whole box is switched thru a toggle on back. It has 3 Peat-repeat PP-1 modules, 1 preprogrammed "Convoy" module. I figured the power switch would let me reprogram without disconnecting anything. I plan to put jacks in the box to each module so I don't have to open it to program them. The between the power cord and the switch on the back is also connected to the mic audio pin.

I am using a D104 Silver Eagle for the mic, a Galaxy DX 939 and a Galaxy DX 88HL.

My issue. The 939 talks great, the mic gain is at least 80-90%. When I turn it off and turn on the 88, the 88 squeals unless I turn the mic down to about 30%. Both radios have been set up by the same person, both have the AML circuit still. Power output doesn't matter. I am using 2 cobra external speakers, they are about 3' from the mic, 88's is actually turned sideways to reduce feedback squeal.

If I leave everything the same, just disconnect the sound box and plug the mic directly in to each radio, I can turn the 88 up to almost 100% on the mic again. My wiring for the 4 plugs, is bottom, top, right, left, if you are looking at the box from the front. I have moved connections around, and no matter where I plug in a mic or radio, it still has the same effect.

Is the 88 more sensitive to something? Would a filter of sort work? I already have a ferrite snapped on the mic input jumper at the radio end, the wire makes one loop around the ferrite. I do not have a ground from the shield of the 4 jacks to the power cord ground, but the radios and the box share power source, so thru the cord, to the power cord of the radio, they are grounded together. Do I need to ground the jacks too?

If pics of inside are needed, just ask.

 

[TheRealPorkchop]

I have one of the Workman boxes here with 8 toys in it, I think it’s 8. On my Magnum S9 it does the same thing but works flawlessly on any other radio I put it to.

I’ve tried a bunch of stuff to remedy the issue when connected to my S9. Doesn’t do it on the bench in the shop but put it all in my truck and it all goes to hades.

Still hunting a solution to this.

 

[sonoma]

I have a factory made box with toys in it and one I made with echo and toys and they will not work on all radios. some I get a squeal when I try to use the toys. the ones I have are aluminum boxes and have tried grounding the boxes and it still would not work in them. so it must be the nature of the beast that they do not want to work on all radios. never tried to trouble shoot the issue any further since I really do not care for the noise toys that much.

 

[OldTech03]

Well, one of the things I have discovered when dealing with these issues is, of course, the radio is part "A" and the noise toy is part "B" so if part "B" works well with one radio and not the other then logic says it most likely is part "A". If that sounds all too simplistic let's expand it a bit and make us all think about the possibilities. Forgive me while I reminisce and act like I'm back in the classroom teaching component level troubleshooting. Now maybe some of you have already tried things concerning this so if you are reading this saying "Hey I tried that" well bare with me for those that maybe didn't.

I would first recommend making sure all the chassis screws that mount the circuit board to the chassis are tight to be sure they are all well synched. These screws being loose can "On some radios" cause all kinds of BS so it's good practice to check these anytime you open the radio up.

First to say that the 88 may be a bit dirtier on the output than the 939 could be an understatement but without the results being produced on a spectrum analyzer it's just speculation but based on having worked on about 6 million galaxies well maybe only 4 million harmonics love to find loose wires to jump on. But first, let's try some other things

I'm approaching this from a "I don't know what has been tried" frame of mind. So please put me in my place if I'm getting too lengthy.

FIRST: Ground looping, Powerline RFI issues some radios are nasty. I have actually spent many hours tracking down these kinds of issues only to find one ceramic or poly bypass shorted or opened which seemed to upset the whole apple cart.

TRY THIS IF YOU HAVE NOT ALREADY. Make a battery pack for the toy box and try, if you can, to place it inside the noise toy box. Now you can do this on the outside with a very short cable about 3 inches long I would prefer it be on the inside this is merely to remove the possibility of RF on the power line feeding back into the Toy Box.
I could recommend some .01 across the power line on the inside of the Box but it's really good to carry out this First test to see if it bears any fruit it may not but it eliminates one possibility and we can then move on to other things that may work or may not.

 

[SIX-SHOOTER]

Never have or will I ever understand Noise Toys? It was always my goal to make the most Beautiful Deep Rich Transmit Audio possible & Noise is the last thing I wanted unless I was using one of my Browning Golden Eagles & they were built that way though by accident originally.The 11 meter band has far to much noise already yet people keep wanting more noise? I hate noise on any band or even in my daily life & just one more reason I LOVE Amateur Radio and have gotten away from almost ever using any of the 100 Plus CB Radios that I own.No echo microphones,reverbs,roger beeps,or other noise toys permitted there & that is a blessing when you hate unneeded & unwanted noise.Some people are obsessed with them when a great sounding transmit signal is far more impressive.Anybody can make noise but not everyone can have SWEET Transmit Audio.

SIX-SHOOTER

 

[OldTech03]

Never have or will I ever understand Noise Toys? It was always my goal to make the most Beautiful Deep Rich Transmit Audio possible & Noise is the last thing I wanted unless I was using one of my Browning Golden Eagles & they were built that way though by accident originally.The 11 meter band has far to much noise already yet people keep wanting more noise? I hate noise on any band or even in my daily life & just one more reason I LOVE Amateur Radio and have gotten away from almost ever using any of the 100 Plus CB Radios that I own.No echo microphones,reverbs,roger beeps,or other noise toys permitted there & that is a blessing when you hate unneeded & unwanted noise.Some people are obsessed with them when a great sounding transmit signal is far more impressive.Anybody can make noise but not everyone can have SWEET Transmit Audio.

SIX-SHOOTER

There is certainly nothing wrong with your position. But I would also say there is nothing wrong with wanting sound makers which many would call "just noise" and you would have many on your side of that subject. My very first response to any problem that is presented to me is not whether I support Why? but one of "CAN I SOLVE THE PROBLEM" So for me, it is all about can it be fixed and after I do I will ask the customer if they are happy not why they wanted to do it. That may not settle well with some fundamentalists but it has served me well over 50 years of making things work.

 

[W2EKG]

 

[TheRealPorkchop]

I work at night paving. It’s fun to annoy the people I work with and they certainly do it in return. With that said, I’ve played a noise toy over the air a grand total of probably 12 times in my entire radio career.

There’s a lot that I don’t support but I still do it if the owner wants that.

 

[TheRealPorkchop]

View attachment 26879

 

[W2EKG]

Drove me nuts when Blue Waffle played that Jetson's doorbell over and over on 38LSB.

 

[Handy Andy]

Perhaps the best answer lies in the construction revisions and layouts...

This is just the Mic amp section...


The Green areas are Ground from the MIC GND PTT sections.

There are other aspects including mounting PC MIC jack and support parts used - each one is a revision of a previous version....

The rest is up to all the rest of you, approach the problem as if you were the engineer that had to make a good thing even better - and to take the better - and make it the best...

Only in the above? Best, Better and Good - in that order...

OldTech03 said it best...a teaching moment...

Now you may enjoy the journey...

CB Tricks provided the graphics.

You also may want to research Faraday Cage and it's effects.

For it may be necessary to "BOND" the toy box to all the radios via a bracketing system so the cases of each are all at the same potential and are provided the least path of resistance for grounds and shielding to prevent eddy current loops of RF floating about - ruining the effect...

 

[nomadradio]

Just so we're on the same page.

Is there any chance that your feedback howl is caused by accoustic feedback from the speakers' talkback audio?

That would suggest a different solution.

73

 

[jon666]

Never have or will I ever understand Noise Toys? It was always my goal to make the most Beautiful Deep Rich Transmit Audio possible & Noise is the last thing I wanted unless I was using one of my Browning Golden Eagles & they were built that way though by accident originally.The 11 meter band has far to much noise already yet people keep wanting more noise? I hate noise on any band or even in my daily life & just one more reason I LOVE Amateur Radio and have gotten away from almost ever using any of the 100 Plus CB Radios that I own.No echo microphones,reverbs,roger beeps,or other noise toys permitted there & that is a blessing when you hate unneeded & unwanted noise.Some people are obsessed with them when a great sounding transmit signal is far more impressive.Anybody can make noise but not everyone can have SWEET Transmit Audio.

SIX-SHOOTER

me either no toys beeps or flashing lights for me ever

 

[543_Dallas]

I had a feedback issue with a pp1 in a magnum S9 once. The pp1 was set up to do an on air recording and play it back.

I believe it was caused by a ground loop. Running the audio through a 10uf cap solved the problem. I used a non polar electrolytic but anything in that ballpark will work. It may not help but is easy enough to put a cap inline with mic audio pin or even the output of each toy.

 

[OldTech03]

Just so we're on the same page.

Is there any chance that your feedback howl is caused by accoustic feedback from the speakers' talkback audio?

That would suggest a different solution.

73

Good question I sometimes assume certain things have already been established as they would be the first thing I would check for. So again Good question.