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How I solved the legal issue of crossband ID


We are already well aware that aside from a select few transceivers capable of crossband repeat, by and large many of these are incapable of IDing both sides of of the VFO, and legally we are required to ID each transmission originating from our auxiliary/repeater station. Crossband repeating according to ARRL's understanding is an auxillary/uncoordinated repeater in most cases. Sure, many don't ID both ways and get away with it but I'm not one that follows the law simply because I may be caught. Plus creating Rube Goldberg machines are fun!

Using a $30 Chinese HT (BAOFENG UV-5RA) and a 2nd generation iPod (ancient) enabled me to solve this ID issue which is documented in the below diagram. As you can see below, all transmissions originating from my stations/QTH are properly IDed -- to date this is working great. An iPod isn't necessary, any audio device capable of looping 10 minutes of audio will work just fine (CD player, voice recorder, etc). I found that wrapping the audio and iPod charging cable around a ferrite helped eliminate what I can best construe as a noisy ground-loop hum that tended to keep the VOX open a little longer than I liked. I set the BAOFENG UV-5RA to the lowest power setting, enabled VOX on setting 2, and fired up the iPod. The attached wavform seems to be the best way to handle the VOX delay ensuring the full ID is received while the transmitter keys up -- I used Audacity (Open Source) since I'm a Linux guy (windows here let the sunshine in).

Comments and thoughts welcomed. I have permission from the repeater trustee to crossband -- for those looking to do this, I highly recommend you obtain permission. Always ensure you have a PL set on your crossband input frequency to avoid keying the repeater during QRN/QRM. When synchronous transmissions occur on 145.45 MHz from the repeater and the BAOFENG IDer the proximity of the HT (6 ft from the antenna) ensures the crossband transceiver captures the BAOFENG UV-5RA signal resulting in 10 minute station ID.

I discovered today was that when the BAOFENG UV-5RA is receiving (regardless of DTCS or TSQL settings) the VOX setting will not trip PTT allowing for TX. Squelch doesn't really work very well on the UV-5RA so my solution was simple -- re-configure the 145.45 simplex frequency as duplex with a listening frequency of 146.580 with a negative offset of 1.13. 145.45 MHz was a little noisy this morning. The trick here is using a low-power HT on the output frequency of the repeater to trip the input frequency on the crossband tranceiver resulting in retransmission of the ID over the "other side" on the crossbanded frequency. Cheap $30 fix to be legal...


Hampton Bays, NY
curious, the impedance between the HT and the iPod for the VOX connection, what is it at ?
i would be curious if strong nearby lightening would trigger the VOX on the HT along with any other stray strong "dirty" AM/FM radio signals that just happen to be close enough (think crazy CB'er).
Suffolk County NY Police Feed - »www.scpdny.com
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Thanks for the response, I'm not quite certain what the impedence is between the connections because I've not measured it but I think the ferrite choke (on both ends of the stereo connection) as well as the improvised ferrite winding does well. I've not heard any TX as a result of induced audio and the VOX setting itself requires high volume -- if you note the audacity wavform the initial square-form audio is required to open the VOX and I had to actually amplify the 'U' in KJ4AUR to avoid the VOX closing at a setting of 2 and iPod volume level of ~80%.

About ~75 ft from the HT is my HF antenna and at 350W CW on 80m-10m I have no induced current/audio. Same with an AM carrier or SSB. I'm inclined to think someone would have to drop a brick on a straight key with a yagi pointed at it to do much. Also note the HT is indoors, in the basement (by the shack), in a home with a steel roof (hi Faraday cage).

Even if I had lightning-induced TX it would be OK since I'm still IDing the transmission. I get your point though, I don't want an 11m cussing rant retransmitted over 70cm since I'm the control operator and responsible for that. It takes a lot for the VOX to open up. I think about 350W ERP about ~75 ft from the setup on 10m is a pretty good test of what I could expect on 11m.

reply to KJ4AUR
I see what you are trying to do, and it looks like a cool and clever set up...but I agree this is a "Rube Goldberg-and-beyond" contraption to satisfy an operating rule that not only do very few hams even know about, I'm willing to bet a ton o'cash that no one, in the entire history of ham radio, has ever been busted on for non compliance. I'm also very confident most of the goody-goody ARRL Official Observers/Radio Cops would miss catching this horrible crime too.

Anyway, you have a cool set up. I give you 10/10 for creativity and follow-through. Bonus point: Very professional looking graphic.

See You On The Dark Side
Louisa, VA

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reply to KJ4AUR
Nice set up.
I personally have never worried about this issue. I used to cross band a lot from my couch in the living room to my shack on the other side of the house. When I would ID I would mention the fact that I am cross banding.
I've never heard or read of the FCC enforcing this overlook on their part...since after all, they have approved the device as being accepted in their world.

I can see a possible problem if cross banding one repeater to another.
But cross banding a HT to a repeater, and being in proximity of the cross-banding device...I don't see a problem, its being done every day, and you can bet the FCC is well aware of it. After all, and again, they approved the device that allows this function to occur.

There are many a Fire and Rescue, Police, and commercial entity's that use cross band in their daily routine of business, and I bet you wont find one that has an ID for the cross banding device in use.

Touchy subject to say the least. And one that has been brought up in the Ham community for years.

But again, I cant see being too concerned over the matter.
I would welcome the FCC to come knocking on my door, or sending me a pink slip concerning my use of cross banding.
Long you live and high you fly, and smiles you'll give and tears you'll cry,
and all you touch and all you see, is all your life will ever be.


reply to KJ4AUR
Thanks guys for the kind words and thoughts, we're all in agreement that this is truly a Rube Goldberg machine and perhaps unnecessary from an enforcement aspect (though I enjoy being legal, even if focusing on the minutia). I enjoyed the challenge and unique solution.

Best wishes and I hope to catch you on the bands. I used 'Dia' to create the diagram -- its Open Source.