XTL Recording

[tuckerm]

I have a mid power XTL 5000 Dash Mount radio I want to record audio off of. Reading the service manual, I can do it with Pin 21 + GND, but will HKN6187B do what I'm looking to do? I would like audio out at a set level, regardless of what the volume is set on the XTL. Will HKN6187B work even though I have a dash mount version?

Thanks,
Tucker.

 

[Astro Spectra]

That cable is for the remote configuration only.

 

[tuckerm]

Thank you for your response. Is there any cable similar to what I posted that could do this or is the only way to do this via the pin outs?

 

[Astro Spectra]

The HKN6187 cable is designed to record both transmit and receive audio. if you only want to record receive audio then you have many more options.

 

[tuckerm]

I only need receive audio recorded...transmit doesn't have to be recorded (it would be cool). Basically, I'm looking for a cable to interface with the XTL 5000 to record all traffic...this isn't for a mission critical system. If such cable doesn't exist, I'll do the pin out method.

 

[Will]

I think it is just adding pin 21 on the P2 accessory plug. Dash mount radio. Pins 1 and 14 are ground.

(3) Fixed level (independent of volume level) received audio signal, including alert tones. Output voltage is approximately 100 mVrms per 1kHz of deviation. The DC offset is 1.4V. Flat or de-emphasis/filtered are programmed by CPS.

So you would also need a blocking capacitor, 2.2 uF plus toward the radio.

I do not see the part number for male pin you need, may be the same as used in 'DB' connectors. There may be a male pin and wire available.


Pin removal tool 6680163F01

 

[tuckerm]

Alright so I was able to take a wire from Pin 21 from the radio. Now, I'm looking for the exact blocking capacitor / other items I need to have clean audio into a 3.5mm audio in to my PC. I've never done this before, does anyone have part numbers and/or links to what I need to purchase? Thank you.

 

[Alpha]

Will told you what you need above, a 2.2 uF electrolytic capacitor, 25-35V should be fine. You can probably use a non-polar electrolytic cap too, but they are harder to find. Print this out and take it to a Radio Shack (if you can still find one!) and they will know what to get for you. If none of your local stores still sells components, you will need to get it from Digi-Key or Mouser Electronics, you can order it online. If you're in southern WI, there's Chester Electronics in Kenosha.

 

[tuckerm]

Radioshack only has one that is 50v, how will this affect what I'm trying to do? My Radioshack doesn't have much, that's for sure.

 

[Will]

"Radioshack only has one that is 50v"

50V that is the voltage rating, that means the capacitor can take up to 50 volts DC before it gets upset. OK for your application.

Four your application, you would need at least 12 volts, and most caps are 15, 25 or 50 volt rating.
This may not be critical, 2uF to 4.7uF works well, 15 to 50 volts rated.

Alpha mentions "You can probably use a non-polar electrolytic cap too," and a non polarized capacitor would be even better.


Why:
The capacitor IS NEEDED to block the DC voltage on the radio's Filtered Audio output. You are after the audio in this case, that is AC, about .1 volts AC. The capacitor will also block the DC on some recorder inputs, for the Mic, from 'backing' into the radio's circuit. If the radio's output is shorted out or a voltage 'backs' into it, the radio circuit will be damaged.

 

[tuckerm]

Okay, capacitor added to the J21 output. I still am not getting good audio, I have a loud buzz and it's quiet on both Digital and Analog. I have one pin going to one wire that I am trying to add a 3.5mm to, and then from there that goes to MIC IN on my recording PC.

This is my audio: View attachment XTL.mp3

Thoughts?

 

[Magnus]

Is this going to a laptop or desktop? Sounds like a difference in potential between your PC and the radio. I hear the same noise when I plug my laptop (AC powered by and inverter) into the aux port on my AM/FM radio. Noise goes away when laptop is running on battery. You may need to dc isolate your ground connection as well.

 

[tuckerm]

Interesting. Do I need a ground coming from the XTL as well? Right now I only have J21 coming from the radio, no pin 1 or 14 for ground. Would this help or hurt?

 

[Magnus]

:bang: Ground is a must, that will probably fix it.

 

[Alpha]

Yes, you must have a ground. Once you get that, the hum should go away. If the level still is way too low, you may need an impedance matching transformer. They are a speaker transformer with one side about 8-16 ohms and the other side about 1k-10k ohms or so. Old transistor and tube type radios used to use them to match the output impedance of an amplifier (fairly high) to a speaker (fairly low). This may be needed because mic and line-in jacks are usually high impedance (10-100 k ohms).

 

[tuckerm]

Success!! I have clean audio. It's a bit hot, but I can work with that and adjust it on the computer side. I really, really appreciate everyones help. I have one final mouth breathing question, Do I need (or should I have) a 2.2 uF capacitor on the ground side as well, or just Pin 21?

Thanks.

 

[Magnus]

No it's good as is.

 

[tuckerm]

Thank you very much.

 

[Will]

"Pins 1 and 14 on the radio connector are ground."


Yes you need a ground connection on the recorder side back to the radio.

 

[Mars]

http://en.wikipedia.org/wiki/Ground_loop_(electricity)