Pro-433 with a JTAG or UART interface?

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datashifter

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I would like to preface this posting with "I am not looking to cause my scanner to receive frequencies or communications which are illegal to monitor."

That being said, I purchased a Pro-433 scanner yesterday evening. It was on clearance at the RatShack for $119.99 + tax. It's the first trunking scanner I've owned, and the only other scanner I own is a RatShack Pro-46.

Today I cracked open my Pro-433 to inspect the test point which user "kd5dga" on this site posted as being a convenient discriminator tap point, labelled as LND4 FM Det. The post I'm refering to is located here - http://www.radioreference.com/forums/showthread.php?t=93667

While I was under the scanner's cover, I noted some key points of interest.

If I have learned anything over my decades of exploring electronics, it would be that anything underneath a black epoxy or plastic blob is typically something which the manufacturer really does not want you to tamper with. Well, there are three black blobs, under which several surface mount transistors, diodes, resistors, and capacitors appear to reside. Interesting stuff for later exploration, but for now the blobs will remain in place on my unit. I have no other trunking scanner, and I do not care to brick my scanner within the first few days of owning it by screwing something up as I scrape away the blobs - although the RatShack does have that wonderful 30 day return policy!

Also of interest is what appears to be an unpopulated 10-pin JTAG or UART header on the main circuit board.

Has anyone played around with the possible JTAG or UART interface on the board yet? I cannot visually the follow circuit traces from the pads to any chips, as the circuit traces are embedded within the PCB's inner layers.

I'm asking if anyone has played around with these areas on the board, as it would kind of suck to reinvent the wheel if someone has already been there and done this.

Attached are images depicting the convenient discriminator tap point (labelled as LND4 FM Det.), the potential JTAG/UART interface, and the black blobs.

I anxiously await any replies.
 

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XTS3000

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That sure looks like a JTAG connection from the photo. I'd be interested in viewing the service manual and see what IC is connected to the JTAG pads - that'd tell ya if it's a real JTAG port, or maybe a serial PC internal connection (for use at the factory during production to load some preloaded freqs).
 

datashifter

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Looks as if, from preliminary inspection, the potential JTAG/UART port is routed to the CPU located underneath the below depicted shield.

At the moment, my soldering irons are not handy, otherwise I would be taking a peek under this shield to see what CPU makes this puppy tick.

Note the 10-pin unpopulated header to the top-left of the shield - this is the possible JTAG/UART port.
 

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kd5dga

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Datashifter,
Thanks for my reference to the discriminator tap point. I am not that good at loading up pictures and my digital camera bit the dust last year when I took it on a trip. The camera was cheep. About the uarts tap point , I am very interested and will follow the forum here. I am not an electronic engineer but I do enjoy scanning and modifying as a hobby and if there is more to do with this scanner I am always up to it.
I have used my PRO433 for discriminator output for many programs (unitrunker,LTR Analyser)with good results.Its a afordable radio with many capabilities. I think that the PRO2055 out performs on LTR trunking. I am glad that someone was able to post a picture of my findings. Thanks again.
 

DickH

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Has any progress come of this?

If you want the service manual, you can order it from any Radio Shack. The trick is to find one with someone working there who knows their way around the RS computer system.
I believe it is an RSU part, 12449039 MANUAL SERVICE 20-0433.

It's only about $5 plus shipping. and it comes on a CD. Mine included a paper copy of the schematic.

It is very complete with alignment instructions and setup, IC connections, etc., etc.
 

datashifter

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RadioShack no longer carries RSU, 12449039 MANUAL SERVICE 20-0433 as a part for sale.

I would love to obtain a copy of the service manual. If anyone has it available, please let me know.


Thanks!
 
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