Last night a mystery sound got noticed, sounding like loud talking just on the other side of a wall or maybe in the basement. I ran through a mental picture of every radio in the house, but I knew they were all tuned to KDX and whatever I was noticing was something else. So I stepped outdoors and realized it was a highly amplified church service one block uphill from here. I started wondering how the congregation was tolerating so many dB and I wasn’t about to go there and subject myself to hazardous hearing, but I wondered what the all-fire sermon was about.
It was likely they were using a wireless mic, and just maybe I’d be able to listen to their frequency if I knew where to look. And I got to wondering, does anyone DX on the wireless mic frequencies? Seems like it could be fun.
If you were at a sporting event which was being broadcast, you could listen to director’s cues to camera operators.
Near a TV studio who knows what could be heard.
mram1500 says
RF Alley…
Located about 600 feet behind my property running parallel to my street is Howe Avenue, a hustling-bustling commercial area lined with retail on both sides of the street between Main Street and Tallmadge Avenue.
I can routinely listen to the Wendy’s, McDonalds, Burger King, etc. drive thru window order wireless mics.
Also, several stores use 460 mHz GMRS for their personnel to stay in touch with each other.
There was a church on the corner of Howe Avenue and Buchholzer Boulevard. It has since been razed and a CVS Pharmacy built. When the church was there, Sunday sermons could be picked up around 170 mHz from their wireless mic system.
The area is rich with a variety of RF use.
RichPowers says
I had bought a real cheap
I had bought a real cheap wireless mic. The 1’4 jack has a short little wire coming from it that receives the mic xmtr.. I was thinking of extending that wire so it would go outside the building, and then occasionally using the mic to on the sidewalks in the immediate area for some very brief interviews with tourist during the peak of the season when the sidewalks are full.. It’s just a thought.
I haven;t experimented with the mic yet, and don’t even know if running a long wire outside will even do the trick – but only paid about $12 for it on ebay, so if it doesn’t, then there’s no big loss.
RFBurns says
Long wire
I was thinking of extending that wire so it would go outside the building
That might work. Thing to keep in mind is that extending the wire may cause the receiver to pick up unwanted noise as it’s front end is most likely tuned and peaked for the short wire on the connector. Adding more wire may make the front end overload or become too sensitive and pick up junk.
I would try to sit the receiver in a window facing the area of the busy sidewalk. If the distance is not too great, that should work as well.
RFB
RichPowers says
I would try to sit the
I would try to sit the receiver in a window facing the area of the busy sidewalk. If the distance is not too great, that should work as well.
Well Carl, it’s a real cheap wireless mic. I cant put the receiver in the window, the receiver is matchbox size with a 1/4 jack sticking out of it! http://i.ebayimg.com/03/!B8cCgfwCWk~$(KGrHqR,!lsEy+jCw6G3BM3DEbryNg~~0_3.JPG
It was an impulse buy, brand new, and it seems to have a decent weight to it, but I think it must be just a toy…
(what just came to mind is one of your shows where you talked about some garbage mic you took out of some contraption that ended up sounding great…. which reminds me of something else, I mentioned it a couple weeks ago, and still think your “Canned Chili” episode from long ago would make a appropriate supplement to categorize under the Low Power Hour page.. but anyway, ..what was I talking about? — Oh yeahh.. the wireless mic..)
.. and I’ll probably toy with it and see what it can do, but if it cant do it, and the sidewalk thing becomes something I really want to incorporate then I guess at that point I’ll get a better mic for it.
MICRO1700 says
DXing wireless mikes
It’s hard to do. They are all over the spectrum. My
brother does have a new Uniden trunking scanner.
One feature this scanner possesses is the ability to
instantly display the frequency of a nearby signal.
But I imagine it would have to be very nearby.
More than 20 years ago, at a stay in Massachusetts,
I also stumbled on a signal from a local establishment.
I think it was a McDonalds. The signal was down
somewhere in the VHF low band between 30 – 50 MHz.
You could hear the person taking the orders from
the customers in their cars. My friends were amazed that
I could pick it up on my scanner. It must have been
a mile away. It did get old very fast. By the way,
the 30 to 50 MHz public service band used
to be a wonderful place for DX listening. Especially down
on the low end at the height of the sunspot cycle. You
would hear small town communications from all over
the country. I haven’t listened down there in years.
I wonder what it’s like there now?
Best Wishes,
Bruce, MICRO1690/1700
scwis says
Not DX, but monitoring, nonetheless
Having the good fortune to have lived in some fun locales, wireless mics have been a fun catch on my scanners. I live near the old Kingdome in Seattle WA during the 1994 NCAA final four and heard a bunch of behind the scenes stuff.
Later I lived next door to the Moore Theater in Seattle’s Belltown district and enjoyed performers and security communications. Living in Portland I was able to catch the Rose Garden (NBA area and multiuse venue) mics.
Even if you don’t live near a venue (and only if legal in your location) a drive by on a busy night can be lots of fun.
And speaking of driving – I find myself keeping 87.9 tuned in to catch the many in-car transmitters folks use these days and 87.9 is a popular vacant in this area.
Carl Blare says
Nothing Now
Based on MICRO1700 comment, I just scanned 30 to 50mHz but there was nothing now. I’ll check it at different times.
Also, being a block from a highway, 87.9 might be worth catching, except we have a “big” station at 88.1, so maybe around here things will be at 87.7.
I’ll find out and be back.
RFBurns says
LowFerMin
we have a “big” station at 88.1, so maybe around here things will be at 87.7.
Did not know there were any Part 15 FM TX’s that would hit 87.7….much less typical consumer FM car radio receivers tuning that low. The old TV ch 6 audio carrier is 87.750 Mhz. Good thing there are no more analog TV stations down there eh?!!
RFB
Carl Blare says
One Does
One Part 15 certified transmitter does all three lower channels: 87.5, 87.7, 87.9
It is the Schosche FMT4R which was at Walmart for $10. It works so well I bought about 4 of them.
In earlier threads we entertained the idea that the lower frequencies weren’t supposed to be part of the certified authority, and the FCC info posted for the transmitter did not list those lower channels.
RFBurns says
Made in…somewhere besides the US
It is the Schosche FMT4R which was at Walmart for $10. It works so well I bought about 4 of them…..and the FCC info posted for the transmitter did not list those lower channels.
Well take a look at the label and see where those are manufactured. That would explain why they can go that low. One design fits all..so to speak. Helps keep manufacturing costs down by making a unit capable of covering both our FM lower band and part of the odd ball FM band in countries where their FM band begins much lower than 87.9.
From another site:
Apparently, it is available from Wal-Mart but from what I gather reading around a bit, this thing is likely not legal…it’s also not shown nor referenced anywhere on the Scosche website that I could find.
A quote from a comment in the linked topic below:
“On the other paw, it’s Wal-Mart. They can get away with anything.”
http://www.poi-factory.com/node/25132
Does your units have an FCC ID number on them?
http://www.part15.us/files.p15/nabp15.pdf
Different model numbers, and the report is dated 2006….but even for that year and model number….I would hardly consider them as Part 15 legal.
I would put those away or just use them within the LEGAL frequency allocation of the US FM band if you use them at all. Again I have not seen any typical consumer vehicle FM radio (digital tuning) capable of tuning 87.5 or 87.7, majority quit at 87.9, with the exception of the old manual-tuned, sliding ferrite slug types which could tune that low, sometimes even lower.
I can see why they “worked so well”…considering the field strength those things produced..close to 1db within the limits…like riding the very edges of the steep cliff.
RFB
Carl Blare says
Scosche Information
Custom manufactured in China.
FCC link
https://fjallfoss.fcc.gov/oetcf/eas/reports/ViewExhibitReport.cfm?mode=Exhibits&RequestTimeout=500&calledFromFrame=N&application_id=864314&fcc_id=%27RLQAT100%27
There has been mention of opening “the core tv band for use by part 15 devices” and that a temporary waiver is in place pending a final ruling, but take caution with this remark, it is what I remember encountering in the sea of literature, although I think discussion of this has been made here on the site.
The Comtek FM transmitter covers these frequencies and has been usable under Part 73, but there is the possibility of use under part 15 may now be covered by the “waiver.”
On a relevant link I think a member has contacted Comtek but received an indecisive reply.
Now that I have sprinkled rumor and innuendo perhaps all this can be re-checked.
Carl Blare says
The Comtek FM Transmitter
One of our members brought attention to this interesting device
http://www.comtek.com/bst25.html
RFBurns says
RPU
Well that is a nice device….for 74 use.
As to the opening up the lower VHF of former analog tv…that will end up going to first bidders of existing licensed AM stations…..count on it.
Now when that does happen, perhaps there may be hope for us TINY stations to get attention on the rule making floor. However unlike some who want to gladly throw themselves to the tiger’s paws and shark’s jaws and become tangled up in RED tape and everything else that comes along with licensed stations….personally I do not wish to participate in a highest bidder contest of radio channels..rest assured, that is what will come about for a LPAM service…and all the endless dregs of doing paperwork instead of running the station, as well as special interest group hogging it all up…like one I have heard of that is about to do just that..on a certain program….under the umbrella that is no different to what happened and resulted with LPFM.
First the LPAM would have to be a viable market..that is generate enough $$$ upfront for the FCC to even consider it. Second, the BIG time NAB aint going to let that easily slip through the back pocket padded system, and third..the relocating of existing licensed AM stations will have to have a serious benefit to move from the existing band up to the VHF low band, which means a total change of the entire TX and antenna systems…not a cheap venture, plus the re-educating of their listeners, AND…and this is the big thing…the making of new radio receivers with the ability to tune down into the old tv low band channels…..again another thing that will have to be profitable for the receiver manufacturers which covers not just those little portables or specialty radios, but car radios and home stereo systems. Oh sure they could make adapters, who is going to clutter up the dash board with more clutter already taken up by add on GPS and iPod FM transmitters and cell phone chargers!! And lets not forget the existing uses of the VHF tv low band with the very item you liked to…a part 74 device for use in the RPU services.
Let’s see if the first MAJOR hurdle is overcome with the existing licensed AM stations making a MAJOR move…if that happens…MAYBE other things will fall into place….MAYBE.
RFB
MICRO1700 says
30 to 50 MHz Info
Carl – just wanted to mention this.
I did most of my 30 to 50 MHz listening
20 or 30 years ago. So many users have left
the band to go up higher – such as the
450 MHz band or 800.
In the fall of 1991 (oh my gosh no – it was
1981 (!) on one particular Saturday morning,
I decided that I wanted to monitor 30 to 50.
I needed a receiver, and I walked down to Radio
Shack and purchased a tunable portable that
had 30 to 50.
I took it out of the box and plugged it in. Oh man!
The whole band was COVERED
by strong Spanish language transmissions. Up at
the top of the band, I heard a strong morse code
station – and the radio had no BFO but the
signal was so strong it didn’t matter. It was a
ham station in California (!) and I was in Connecticut!
He was on about 50.020 MHz. The radio was
on my kitchen table with just the whip antenna!
I verified this fact with a six meter ham converter
hooked up to a general coverage receiver.
And ten years later, I remember two other interesting
things that happened in the 30 to 50 MHz range.
Somewhere around 46 MHz (?) in the afternoons, I
would hear a sporting event that would go on
for hours. I heard it for weeks. It was in another
language and has always been a mystery. I
wonder if it was the sound from a foreign TV
channel??? I wish I had kept better records.
Then there was the other thing that was
amazing. The BBC used to transmit on
15.070 MHz all the time. Imagine my
surprise when I came upon the second
harmonic on 30.140 MHz! This was with
my Radio Shack PRO-2005 scanner in
the AM mode. The antenna was just
what was on the top of the radio!
Boy, those were the days!
Bruce,
MICRO1690/1700
Carl Blare says
Moving Up
I’m glad you told me that 30-50mHz is not so much used anymore. I’ll go up higher to where more is happening.
Last night I spent a second session going over these channels, but still found nothing.
Another thing I sometimes wonder is what I have found up in the above 108mHz… probably 200mHz area…
People giving each other messages, but I don’t know what or where they are, and long downtimes between transmissions.
MICRO1700 says
Hi Carl!
Well 225 – 400 MHz is where military aircraft coms
take place, but I’m not sure if you were in that
area. Around 200 – well I’m not too sure – that is
the middle range of RF TV channel 11.
Could you tell me any more? I think that the law
says you cannot say what they were actually
saying – that is – their actual words – but maybe
you could describe in broad terms what they were
talking about.
Bruce, MICRO1690/1700