AEA PK-232 TNC Help

[blindfire]

I am trying to get into PACKET/PAKTOR for NTS work. I an borrowing a buddy's PK-232 PakRatt. Problem is, there is now power supply included. It just has the 2.5mm jack. The radio itself say it needs +13 VDC. No amperage rating on the unit. Online documentation seems to say that it will work at 12 VDC @1000mA. Ok...cool.

Problem I am having is determining if the jack is tip positive or tip negative. My Google-Fu has failed me here.

Anyone have any ideas?

 

[BillT113]

The Center pin of the coaxial power plug is POSITIVE. Page 5 of 91 in manual. Here is a link to the manual. Just noticed this is for PK-232mbx I would think it is the same though

https://www.google.com/url?sa=t&rct...L8YFfcK_z3lUflgFw&sig2=QoHatLWKmXOGFZQVlQ0cXA

 

[vicorjh]

Interesting. Don't know anything about those but, if similar, the PK232TM specifies 13VDC tolerant to 12 - 16 VDC at 700 mA.
http://www.repeater-builder.com/aea/pk232/pk232-tech-ref-manual.pdf

Digging in, the schematic illustrates an LM317T voltage regulator set to produce an internal 5VDC power rail. This regulator is "beefy" and can handle a wide input range and theoretically would work down to around 7VDC for a 5VDC rail.

Although, there are several circuits that are driven/biased directly by the input supply including a power-on reset circuit and what appears to be some amplifiers. This configuration along with the decoupling cap ratings probably define the upper and lower limits to the input supply. The condition and rating on the caps would be my primary concern.

On that, I think you should be fine with the 12VDC. I don't see a path that will let the smoke out as long as the caps are in good condition and you are below the maximum. I'd connect it up like BillT113 says ensuring that the tip=12VDC and the ring(outside conductor)=GND.

I can't tell for certain from the schematic but if they are biasing some amplifiers directly from the input supply, at some point you may want to ensure that the power supply isn't too noisy (e.g. avoid cheap Chinese knockoffs) as well...

 

[blindfire]

Thanks guys. Talked to a buddy who has this same unit and got the same info.

Created a cable. Verified that the tip was the wire with the white stripe on it, soldered it to a power pole cable I'd made previously. Shitty job of it as I am faking it when it comes to soldering...but I got them connected and ran a continuity check for both and it worked. Wrapped the solder points in electrical tape and tested it out.

I have two of these. The guy I am borrowing them from made me the deal that if I could make them both work, I could keep one. COOL!

Problem is, the first modem didn't power up and so I thought it was my cable. Grabbed the second modem and it did power up! YAY!!!

Upon closer inspection, the pin on the power connector on the first modem was very loose...so I think it broke free from the MB. I've got another friend who said he'd take a look at it. He's got 20/20 vision...I don't.

Thanks again!

 

[blindfire]

Ugh...the saga continues.

I had to factory reset the working PK-232. No matter what serial connection parameter mix, I could not talk to the box. So, I pulled the jumper off of the battery and let it sit. Booted it back up 5 min later, and BOOM...serial access to the box.

Now the issue I have is getting the modem to key up the mic on my Icom 7100. I've gone through all of the settings on the radio and have done some google searches. Those searches lead me to believe that you can't key up the radio via the DATA port. This makes sense based on the menus on the radio. The mention ACC and MIC as options, but not DATA. Going to call Icom today and confirm. For all I know, this could be for naught.