Interesting comments being filed with the fcc on unused 46Mhz/49Mhz pairs

[WRYZ926]

32 minutes ago, WRTC928 said:

Your information may be out of date. There are active 70cm amateur repeaters in both Midwest City and Del City Oklahoma, both of which are adjacent to Tinker Air Force Base. 

My information may be outdated. Though last time I checked there are not any 70cm repeaters allowed around certain air bases in California.

[WRTC928]

7 hours ago, WRYZ926 said:

My information may be outdated. Though last time I checked there are not any 70cm repeaters allowed around certain air bases in California.

We may both be right; it may have to do with the type of operations they conduct at that base. Just an educated guess, but I spent 14 years in the Air Force. 

[WSDD519]

On 5/16/2025 at 11:10 AM, 73blazer said:

My parents still use a 49MHz cordless phone system in their house. I never looked at what type is was before until just a couple months ago when we switched them from AT&T's rape job $110/mo landline to a $6/mo VOIP service. My dad just got some new batteries for the handsets last year!

I used to have fun eavesdropping on the neighbors cordless phones.  Some interesting conversations

[WRUE951]

13 hours ago, WSDD519 said:

I used to have fun eavesdropping on the neighbors cordless phones.  Some interesting conversations

Yup, use to do that all the time,  even analog cell freqs using field strength metters

[Ian]

I also feel like MURS and FRS ought to be merged, since their rules are so close to identical.  This would mean removable antennas on FRS radios, which… should be mostly a nothingburger with a few "duckheads" running amplifiers to create high-powered jamming equipment but… you can already do that today, it doesn't happen, so we shouldn't be forced onto fixed antennas because stupid people want us to not have nice things.  Seriously, it's a non-thing.  Time to drop it.

[Ian]

On 5/3/2025 at 9:19 PM, OffRoaderX said:

So you'd need two different radios, or one radio with two different antennas to make use of these and the existing GMRS channels?  Does not seem very user-friendly... If they are unused, throw 'em to the H.A.M.s.. they'll use it.. they'll use anything.

This is smack in the middle of the "magic band", which is especially suitable for meteor-bounce communication and other really weird shit.  We'll do fun propagation science to it, even if we need to buy a GMRS license to do it.

 

On 5/3/2025 at 10:37 PM, Radioguy7268 said:

Before you get too excited about the long range possibilities of a low band repeater, talk to anyone who has actually built one, or tried to use one.

Beyond the problems of skip, near-far, and antennas that can double as fishing poles, you also find out that you need to have one antenna tuned for the transmit frequency, and another tuned for receive. Typical bandpass cavities are 5 ft. tall, you will need enough space for at least 6, and you better keep them in a climate controlled environment, unless you want to keep a separate set tuned for each season.

You also need to know that a typical low-band mobile antenna is only good for about a 500 KHz spread while your proposed pair is 3 MHz apart. Noise is a huge problem, terrible at times. It's only gotten worse in the last 25 years.

There's a reason why Commercial (paying customer) Low-band has become a wasteland. Actually, there's many reasons beyond the ones I've mentioned. Most manufacturers have abandoned the band.

That sounds just about fucking ideal for linking repeater sites over the air.  How much digital data can we squish into the CTCSS frequencies?  Something like AllStar without internet interconnections should be rules-compliant.

[Lscott]

2 hours ago, Ian said:

also feel like MURS and FRS ought to be merged, since their rules are so close to identical.  This would mean removable antennas on FRS radios,

Maybe not a bad idea. One could pick the frequency band that works best for the local conditions without being forced to carry two radios. The removable antenna bit could be a hangup issue however with the FCC. Otherwise no real technical difficulty. Hams had dual band HT's radios for decades.

People have been doing this on the sly for a long while ever since dual band radios were around with the MARS/CAP mod's, or the opened CCR's like the UV-5R.

[WRYZ926]

2 hours ago, Ian said:

This is smack in the middle of the "magic band", which is especially suitable for meteor-bounce communication and other really weird shit.

Actually it is right below the 6m band which is 50.0 MHz to 54.0 MHz.

The US Military still uses 30 MHz to 70 MHz. Some source state 30 MHz to 75 MHz or 88 MHz. This includes the frequency hopping SINCGARS radio system. 

Yes 46 MHz or 49 MHz could be used for public two way coms but that portion  of the VHF spectrum can be fickle hence calling the 6m band the magic band as it is either open or closed and you never know which it is. And openings don't stay open very long.

[WRYZ926]

2 minutes ago, Lscott said:

The removable antenna bit could be a hangup issue however with the FCC. Otherwise no real technical difficulty. Hams had dual band HT's radios for decades.

People have been doing this on the sly for a long while ever since dual band radios were around with the MARS/CAP mod's, or the opened CCR's like the UV-5R.

It would be easy to make a dual band antenna that covers MURS and FRS/GMRS. It's done all of the time for 2m and 70cm dual band radios.

Tri band and quad band hand held radios generally require two antennas: one for 2m/70cm and another for 1.25m and 6m.

The cat's out of the bag when it comes to actually separating FRS from GMRS. I doubt that will ever happen. But I could be wrong on that.

[Lscott]

3 minutes ago, WRYZ926 said:

It would be easy to make a dual band antenna that covers MURS and FRS/GMRS. It's done all of the time for 2m and 70cm dual band radios.

Both MURS and FRS lie just above the Ham 2M and 70cm bands. 

The ratio between the mid point of the 2M band frequency range to the mid point of the MURS band is 0.953.

The ratio between the mid point of the 70cm band frequency range to the mid point of the FRS band is 0.946.

It's an almost identical ratio so a simple reduction on the element length would likely work just fine for both to modify a Ham dual band rubber duck antenna.

[WRYZ926]

Some dual band 2m/70cm antennas already work for MURS/FRS with acceptable SWR of 2.0 or less. And you are correct that it would not take much to dual band MURS/FRS antennas with just small changes to the element lengths.