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Author Topic: Midland 75-160 FCC ID: F9GRC-3000 - 3 Channel FM 27 MHz Walkie Talkies Part 15  (Read 740 times)

Offline R4002

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Edit:

I got my hands on two new in box 75-160 handhelds.  They are FM, and the channel frequencies are:

Channel 1 - 27.095 MHz FM
Channel 2 - 27.145 MHz FM
Channel 3 - 27.255 MHz FM

The FM deviation appears to be 5 kHz.  I checked using a multi-norm handheld set to the Poland band plan - AM/FM CB and was able to hear 27095 pretty much loud and clear on 27.100 MHz Channel 12R.  Same with 27145 coming in nicely on 27.150 MHz Channel 16R. 

Channel 3 is indeed 27255, CB channel 23 and I was able to hear RCRS data bursts on it.  Apparently a single-channel variant the Midland 75-150 FM Walkie-Talkie was also sold.  It advertises 1/2 mile range just like the 75-160 3-channel 27MHz FM walkie talkie box does. 



So I went on a bit of an eBay binge, ended up ordering a Maxon 49-HD 49MHz 5-channel FM walkie talkies and RadioShack TRC-512 / TRC-503 5 channel 49MHz handhelds, 27MHz paging transmitters (RadioShack PG-80, and Command Communications PrivatePage PS2000AN pager - which is similar to the RadioShack PG-99 pager 17-6020)

…and pair of Midland model 75-160 3-channel 27MHz FM Walkie Talkies. 

FCC ID F9GRC-3000 F9GRC3000

These indicate FCC Part 15 compliance on the back of the radios.  3 channels, indicated as 1/2/3 on the side of the radio.

FCC type acceptance date is 13 June 1991  - formatted as 1991-06-13.  FCC rule Part 15C, Grant Note 37.  Operating frequencies 26.96 MHz - 27.27 MHz. 

FCC Grant Note 37:


I found a thread on an Italian language forum about it being a “civil band” or “urban band” (CB radio) walkie talkie with 2-4 km range and it likely operating on 27.120 MHz.  Nothing is said about the 3 channels. 

https://www.elforum.info/topic/98890-statii-portabile-walkie-talkie-midland-cred-ca-destul-de-vechi/

Since these aren’t 49MHz handhelds and they’re FM mode they are intriguing to me.  They appear to be early 1990s vintage. 


One thing is the operating band for 27MHz Part 15 has changed very slightly over the years.  Now it’s 26.96 MHz - 27.28 MHz.  Old versions are 26.97 MHz - 27.27 MHz, 26.96 MHz - 27.27 MHz, etc. 

26.960 MHz - 27.270 MHz is the one that matches with this radio.  I know 15.227 is the same as 49.82-49.90 MHz in that it’s 10,000 microvolts/meter at 3 meters. 

These radios are listed as 1/2 mile range radios, which to me says more than the 12 microwatts or whatever 10,000 uV/m at 3m is.  Seems more like a 50mW to 100mW type rig…like the old 100 milliwatt single channel RadioShack handheld CB rigs TRC-91 or TRC-92 and several others. 

On another tangent, these could be turned into legal 11m 27MHz Part 15 beacon transmitters.  A blurry image of the radio’s PCB clearly shows a set of 3 crystals and another set of 3 crystals, likely a transmit/receive pair for each of the 3 channels. 

Once the radios arrive I’ll figure out what channels these things are actually on.  Since the operating band is 26.960 - 27.270 MHz, I’m assuming some combination of the RCRS channels…26.995 MHz, 27.045 MHz, 27.095 MHz, 27.145 MHz, 27.195 MHz and 27.255 MHz.  Avoiding 27.255 would make sense but who knows. 

Since it’s Part 15, in theory, it could be any 3 frequencies in the 26.96 to 27.27 MHz range, 27.120 MHz, 27.240 MHz and 27.250 MHz or whatever. 

Hopefully I’ll be able to update this thread with another piece of 27 MHz walkie talkie  history.  Now that FM is legal on Part 95 Class D CB radio, regular CB channels would be okay, but the RCRS channels are better for a potential beacon project. 

I’m interested in knowing what, if any difference in the associated Part 15 section 15.227 (47 CFR 15.227) in effect when these radios were approved. 

Also, what does this mean? Grant Note 37

FCC Grant Note 37
FCC Grant Note 37 signifies This device has shown compliance with new rules adopted under Docket 87-389 and is not affected by Section 15.37, transition rule

Here’s FCC Docket 87-389

https://docs.fcc.gov/public/attachments/DOC-342985A1.pdf

Does anybody have a copy of Part 15 as it was in 1991?
« Last Edit: November 29, 2023, 1342 UTC by R4002 »
U.S. East Coast, various HF/VHF/UHF radios/transceivers/scanners/receivers - land mobile system operator - focus on VHF/UHF and 11m

Offline R4002

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I’ll be doing some testing with these and the 49MHz gear and will be posting the results on YouTube and on here as well.
U.S. East Coast, various HF/VHF/UHF radios/transceivers/scanners/receivers - land mobile system operator - focus on VHF/UHF and 11m

Offline R4002

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Actually, the channel frequencies may be wrong.  I need to open these radios up.

FM audio quality is much better on:

27.100 MHz FM for Channel 1
27.150 MHz FM for Channel 2
27.240 MHz FM for Channel 3

instead of

27.095 MHz FM
27.145 MHz FM
27.255 MHz FM


I checked 27.250 MHz as well, which resulted in distorted audio.  27.255 MHz is very distorted.  I need to check these and actually look at the crystals. 

Interesting pieces of equipment.  According to the FCC ID documentation, they operate anywhere between 26.960 MHz and 27.270 MHz.  27.1 MHz, 27.15 MHz and 27.24 MHz do fall within that band.  I guess I just assumed they would be exactly on
26.995 MHz
27.045 MHz
27.095 MHz
27.145 MHz
27.195 MHz
or
27.255 MHz

Using the “in-between” frequencies actually does make sense to a certain degree, with the high FM deviation the possibility of adjacent channel AM voice QRM is lowered at least some.   The Italian forum talking about these radios claims they’re on 27.120 MHz FM.  It also indicates 2km to 4km range, which is pretty impressive for Part 15 if that’s actually the case. 

The box says 1/2 mile, which is not 2-4 km.  1/2 mile is 0.8 km 800 meters. 
U.S. East Coast, various HF/VHF/UHF radios/transceivers/scanners/receivers - land mobile system operator - focus on VHF/UHF and 11m

Offline RobRich

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You *might* get 1-2  miles with absolute clear line-of-sight comms on ~27MHz assuming Part 15 compliant output. Toss any significant obstructions in the path, and figure more like a few hundred meters or much less. If the antennas are short unloaded whips, once combined with the already low output, expect the "much less" due to potentially significant RF losses.

IIRC, my local distance record with a 27MHz handheld was around 15 miles. That was in the East TN mountains with plenty of obstructions. So it was not line of sight, and that is quite short for most any upper-HF daytime DX propagation mode. Then again, for all I know the other op could have had a multi-element yagi pointed in my direction.

Anyway, the radio was an old GE 40ch AM handled. Basically this model or a sibling:

http://www.radiopics.com/CB%20Radio/USA%20CB/1-Handheld/General%20Electric/General%20Electric_3-5979A.htm

To my benefit that model had up to 3w output and an integrated 57" center-load vertical antenna. IIRC, I think it was running on 12v instead of batteries, so the 12v power cord was likely acting as a counterpoise as well.
« Last Edit: November 30, 2023, 2146 UTC by RobRich »
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Offline R4002

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I actually recently picked up a few TRC-224 3-channel CB handhelds.  The crystal controlled ones with "3 watt output".  They actually are 1.5 watt output (on high power). 

They've got massive center-loaded telescopic whip antennas.  I've got plenty of crystals to play around with, including some for 27.675 MHz, 27.725 MHz, 27.775 MHz and 29.825 MHz (TX and RX crystal pairs).  Plus a few extra TX/RX pairs for CB channels 11 and 30 and maybe a few others.  Yep, you read that right.  29.825 MHz.

As far as going the distance with CB handhelds, my past experience with the 3-channel "3 watt" RadioShack/Realistic HTs like these are the winners. 

I also recently acquired a handheld CB that does AM and FM.  PNI Escort HP 82.  Nice little rig.  Plus, it has the same "Kenwood Style" audio connector that all the Baofeng, etc. Chinese handhelds have.  So, in theory (and I've tested it, it does work) I could set up my own simplex repeater on CB.  The PNI HP82 comes with one of the adapter plugs that has a cigarette lighter plug for 12VDC / 13.8VDC as well as a pigtail with a SO-239 socket on the end to plug it into an external antenna. 

On the topic of the Midland radios, they are very wide FM (receive and transmit).  On "Channel 1" (27.095 MHz) I could hear AM CB skip coming in very clear.  Naturally the big signals from 27.085 were coming in but I was hearing 27.105 MHz and others mixing in.  Same when I tuned to 27.145 MHz and whatever channel 3 is (27.240 MHz?  maybe 27.245 MHz?)  The FM deviation is so wide that it doesnt seem to matter.  It also explains my difficulty in figuring out exactly which frequencies these two Midland 75-160 handhelds have in them...because I was trying to do so with a quite narrow FM FM CB radio. 

More experimentation to come.  I don't expect much.  49MHz Part 15 like range.   

The TRC-224 rigs show more promise.  Plus, its much easier to swap crystals in and out of them, they have a connector for an external antenna (RCA type connector, I did get some RCA to SO-239 adapters and some coax jumpers, PL-259 to PL-259, PL-259 to SO-239 - various lengths, etc.  Since I need coax for the Pager Beacon II project. 

U.S. East Coast, various HF/VHF/UHF radios/transceivers/scanners/receivers - land mobile system operator - focus on VHF/UHF and 11m