scannerrail
Member
Would something like that be possible? So you could still have a earphone jack that still worked but if you wanted to switch all you had to do was flip a switch?
Toggle switch for Discriminator Tap?
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John_M
Member
Yes it is possible. You would have to use a toggle switch that has more than one set of contacts though, maybe 6 or 8.
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scannerrail
Member
Why so many contacts?
scannerrail
Member
loumaag said:
hmm did not think about that one I guess that would be better other then having to make a small hole for the jack.
loumaag
Silent Key - Aug 2014
I am confused...scannerrail said:
Your original question was about using the headphone jack (no extra hole required) and putting in a switch (extra hole required.) My reply was, use another jack altogether, which indeed requires an extra hole but no extra wiring and doesn't interfere with the headphone use.
scannerrail
Member
loumaag said:I am confused...
Your original question was about using the headphone jack (no extra hole required) and putting in a switch (extra hole required.) My reply was, use another jack altogether, which indeed requires an extra hole but no extra wiring and doesn't interfere with the headphone use.
Nothing to be confused over...
instead of using a toggle switch which would look a bit odd you could use a headphone jack like you said which is better then my thinking of using an off/on switch.
However I don't have my PRO-95 in front of me right now so not too sure how much space I would have on the side of it to fit a jack.
John_M
Member
I thought about this and it would require 3 to 4 sets of contacts. Then you have to ask yourself toggle switch or jack. Lou answered this question. No accidental toggling of the switch either.
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scannerrail
Member
anyone know what Ohm for the resistor I need?
might as well pick up all that stuff when I go pick the power adapter and programming cable up this weekend.
might as well pick up all that stuff when I go pick the power adapter and programming cable up this weekend.
John_M
Member
A Google search for pro-95 discriminator tap (or pro-97 discriminator tap) gives several sources. When looking for modifications it's good to look at several references to find the one the is the easiest to understand (and to make sure that they agree so you don't follow misinformation).
In a nutshell, you are going to make a connection to TP4 (clearly marked on the circuit board). TP4 is a small wire sticking up from the circuit board. Sometimes modifying electronics is tedious, but with these scanners the manufacturer has made it very easy.
I drilled a hole in the case of my radio and installed a 3.5 mm stereo jack on the case. I ran one wire from the ground on the jack to a ground on the circuit board, and a second wire from the tip connector on the jack to TP4, with a 10 k resistor in the line. (The resistor limit current. Some leave it out and report no problems, but it's cheap insurance. If you don't have 10 k you can substitute another nearby value.)
I used a stereo jack, but only made a mono connection. I connected the tip and the ground (tip and ring), but left the "middle" connection (sleeve) unconnected. This way, I can plug a mono or stereo connector into the radio without having to use an adapter or worry about a short. I use a 3.5 mm stereo to 3.5 mm stereo cable of the type that is used to connect an MP3 player to a car stereo input.
I've seen cases where people have modified the radio to use the existing headphone jack as the modification ouput. It's neater and cheaper, but of course you lose the headphone output. There is also a plug on this radio for computer programming that you could use, but again you would lose another function. On the PRO-95 the case is large enough to easily install another jack.
This output is unaffected by the volume control on the radio, which means you can turn the volume all the way down and not have to go crazy listening to data bursts. Also, the batteries will last longer with the volume down.
It's important to stress that the audio from the scanner must run to the sound card's line input, and that many (most?) laptops do not have a line input. If you don't have a line input you need some sort of external sound card, as mentioned above.
You can get the connector and resistor at Radio Shack. If you're an electronics tinkerer or ham radio operator you may already have everything on hand.
If you draw to much current from the output of the discriminator tap point (Tap + wherever else the tap point goes to, you can overload the output of the discriminator)
which could cause serious problems. Thats why some people use the resister. I would use the resistor. Think of the discrimininator tap point like a 5v 600ma power supply and you try to draw 700 or 800ma out of it.
In a nutshell, you are going to make a connection to TP4 (clearly marked on the circuit board). TP4 is a small wire sticking up from the circuit board. Sometimes modifying electronics is tedious, but with these scanners the manufacturer has made it very easy.
I drilled a hole in the case of my radio and installed a 3.5 mm stereo jack on the case. I ran one wire from the ground on the jack to a ground on the circuit board, and a second wire from the tip connector on the jack to TP4, with a 10 k resistor in the line. (The resistor limit current. Some leave it out and report no problems, but it's cheap insurance. If you don't have 10 k you can substitute another nearby value.)
I used a stereo jack, but only made a mono connection. I connected the tip and the ground (tip and ring), but left the "middle" connection (sleeve) unconnected. This way, I can plug a mono or stereo connector into the radio without having to use an adapter or worry about a short. I use a 3.5 mm stereo to 3.5 mm stereo cable of the type that is used to connect an MP3 player to a car stereo input.
I've seen cases where people have modified the radio to use the existing headphone jack as the modification ouput. It's neater and cheaper, but of course you lose the headphone output. There is also a plug on this radio for computer programming that you could use, but again you would lose another function. On the PRO-95 the case is large enough to easily install another jack.
This output is unaffected by the volume control on the radio, which means you can turn the volume all the way down and not have to go crazy listening to data bursts. Also, the batteries will last longer with the volume down.
It's important to stress that the audio from the scanner must run to the sound card's line input, and that many (most?) laptops do not have a line input. If you don't have a line input you need some sort of external sound card, as mentioned above.
You can get the connector and resistor at Radio Shack. If you're an electronics tinkerer or ham radio operator you may already have everything on hand.
If you draw to much current from the output of the discriminator tap point (Tap + wherever else the tap point goes to, you can overload the output of the discriminator)
which could cause serious problems. Thats why some people use the resister. I would use the resistor. Think of the discrimininator tap point like a 5v 600ma power supply and you try to draw 700 or 800ma out of it.
scannerrail
Member
only thing i don't have is the audio jack I have some 330Ohm resistors is that a bit too much?
And good news is my laptop has a line-input so thats good.
And good news is my laptop has a line-input so thats good.
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John_M
Member
I am not exactly sure where the author arrived at the 10k resistor. But comparing to the 330 its about 30 x less insurance.
scannerrail
Member
John_M said:I am not exactly sure where the author arrived at the 10k resistor. But comparing to the 330 its about 30 x less insurance.
haha left over from a project.. I might have some 10k's left over that I never used.. if Not I can always buy some.
Why bother with all the arfing around when you can install a jack for the tap and be done with it? I believe it was Lou's point to begin with and then you confused the hole thing. (Spekking intentional.)
K I S S... keep it simple stupid! I think I'll go drill a hole in my brain to relieve the pressure.
K I S S... keep it simple stupid! I think I'll go drill a hole in my brain to relieve the pressure.
scannerrail
Member
BECAUSE I don't want to do it that way.. which you seem to have an issue with the way I want to do it.
N4JNW
Member
I think there's somethin in the water... LOL
rail', it's YOUR scanner, do it how you want. I think the guys here are just trying to tell you an easier way, and shoot you some ideas. But, as you may have seen, not everyone's opinion is the gospel..
rail', it's YOUR scanner, do it how you want. I think the guys here are just trying to tell you an easier way, and shoot you some ideas. But, as you may have seen, not everyone's opinion is the gospel..
slicerwizard
Member
So you want to install a switch instead of a jack? Obviously, some don't understand that choice and you won't explain it, so what kind of response did you expect?scannerrail said:
You ask for advice and others give their opinions. Go figure.
Or is it the other way around now? Jack or switch? You seemed to be on the fence for a while back there...
scannerrail
Member
Anyways I installed the jack but I have a question.. somehow after installing the jack I can no longer pick up my local PD it no longer says CNTRL when tuned to 868.7000 I can still receive on other bands.
tapping the Tp4 does not kill me hearing the PD does it? I changed to some other area which is 868.15000 and i hear the sound of a trunked system... is it possible Greenwich switched on me? (seems very unlikely..)
Hmmm it seems like they switched from 868.7000 to 868.15000 I thought I programmed all in the scanner :-/ I guess more reasons to pick that cable up now...
I wonder if it had anything to do with the 5 or so complaints by dispatch about how so many radios were unreadable today?
tapping the Tp4 does not kill me hearing the PD does it? I changed to some other area which is 868.15000 and i hear the sound of a trunked system... is it possible Greenwich switched on me? (seems very unlikely..)
Hmmm it seems like they switched from 868.7000 to 868.15000 I thought I programmed all in the scanner :-/ I guess more reasons to pick that cable up now...
I wonder if it had anything to do with the 5 or so complaints by dispatch about how so many radios were unreadable today?
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scannerrail
Member
oh yeah pictures
w8jjr
Member
Did you use the gas torch to soder the connection . lol .
Looks good
Looks good
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