Did I destroy my scanner or what?

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ETMegabyte

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So I did something dumb...

I have a scanner antenna on my roof (Note that the scanner antenna is also transmit-capable on 2 meters). The coax comes into my computer room/ham shack, where I have a BNC connector on the end (to make it distinct from my UHF/VHF Ham antenna coax). That coax end goes into one side of a "T" connector, the middle connector goes into the back of my broadcastify scanner, the other side goes to another piece of coax into another "T" connector that goes into the scanner that I actually listen to here, and the other side of that connector goes to another piece of coax that just kinda sits there in case I need to connect something to it. Now you have the background...

Normally I use it when I get a radio I'm working on or something, or a scanner, and I want to make sure it receives. Well, I received a new ham radio in the mail today, so I programmed it while it was connected to the scanner antenna.

So, while I'm programming this new radio, someone calls me on the repeater that I just happened to be programming, and without thinking, I picked up the microphone and answered him. The QSO was short, maybe 4 or 5 transmissions from each of us, and none of my transmissions were more than like 3-4 seconds a piece. The radio was set on low power (10 watts).

So here's the problem. One of my scanners, which were connected in-line, now doesn't seem to receive. I did find that if I transmit using an HT right at the house here, it receives that no problem, but anything long distance, I get no signal... I had it set to just listen to a local ham repeater, a repeater that my HT receives just fine with no antenna attached at all, and the scanner detected nothing when the repeater came up...

The scanner that seems to be broken is a Radio Shack Pro-163. The other scanner, which was also connected to the same cable, is a Radio Shack Pro-197 (ACPO-25 capable scanner)... Strange thing is only the non-digital scanner seems to have been affected. The digital capable scanner (my broadcastify feed scanner) still seems to work just fine.

So is this thing junk, or is it just a resistor or something stupid that I need to have replaced?

PS. The picture is of the connector I use to connect multiple radios... The antenna lead comes in the left side, the bottom connector goes to the back of the scanner, and the right connector goes on to the next scanner. I had a hard time explaining it, but figured maybe a picture would help...
 

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davenlr

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Without seeing a schematic, its hard to tell what blew out...probably the 1st rf gain section in the receiver. Just guessing.
 

GrumpyGuard

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I hate to say this but it may be fried. When I was first licensed as a ham I asked Mr. Bob Grove if I could have both scanner and transceiver on the same antenna. The short answer was not with out an antenna switch to isolate the scanner when using the transceiver was in use. He said the power from the radio will burn the scanner as it is not designed to accept such hi wattage, and the antenna would need to be switched between the scanner and transceiver depending on which radio I planned to use at the time.

Sorry to bear such bad news
 

lep

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Ah, Bob Grove before becoming an editor and scanner sales person was a Florida high school middle school science teacher, neither a radio engineer nor antenna expert, just an amateur. However, in this case he is no doubt correct. It is always a BAD idea to connect a sensitive receiver to a coax line with a transmitter without a way of isolating the connection to the receiver. In fact even if there was NOT a direct connection, just having the transmitter antenna CLOSE to the receiver can be enough to damage in RF input circuitry of the receiver by inducing voltage. My suggestion, take this as a lesson learned and modify you setup to eliminate the possibility of this happening again.
 

ETMegabyte

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Well, then I guess I'm glad I blew up the cheaper of the two scanners... The 163 I can replace on eBay for under $100. The cheapest I've found a 197 is from RadioShack.com if I buy a refurb (assuming they have any, which they don't always have)... $300... That would have hurt if I had to replace that one...

Well, I've already bought another 163, and should have it in a few days. I think I'll hand this one off to one of the guys in my local ham radio club and see if he can figure it out... I am encouraged by the fact that it does pick up a transmission from my Ham HT, so it is receiving SOMETHING, but it seems the rf amplifier in it is toast. Maybe it's fixable.. *shrug*

I hate it when I do something stupid. I can't believe I did that... I KNEW better... Just wasn't thinking (shakes head)
 

Nighthawk424

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Yep this is sad, sounds likes you blew it up. It is a good idea to use a seperate antenna for each transmitting radio. For the scanners you can tie them together yes. For many reasons including loss, and of course the sad thing that happened to you.

An old story we used to joke about back in the day was if you had a scanner in your car and an antenna off the back or where have you and the cop that pulled you over did not like it. Well he could walk up to the back with a coax pig tail off of his radio and briefly touch that to the scanner antenna and transmit. Of course then frying your scanner. Of course the same could be said for walking past the back of a COP car and touching your coax to his antenna. Remember most cops leave their car radios on at all times. Anyways this was something we used to joke about but never actually did it. So it sounds like you have learned a lesson here. Sucks I know. Depends on the price of the scanner that is ruined if it is worth taking the time or money to fix it.
 

popnokick

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Buy a new scanner.... the RS is toast, or at best suspect. And stop using T-connectors, particularly on antennas that have some possibility of being used to transmit.
 

jfhtm350

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The good news is that you may be able to sell the faceplate, buttons or some other good part on here so dont throw it away. Seems like someone is always hunting a button plate where theirs is wore out.
 

ETMegabyte

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Suncook Village, New Hampshire
Yeah, I could sell it for parts. I've only had it like 90 days and it's in pretty-much perfect condition...

I've already bought another scanner of the same model, which came in the mail on Wednesday, and since I own ARC-300, it took all of like 10 seconds to get the new one programmed exactly like the old one was :)
 
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