From time to time, the question is raised about using radio equipment in multiple radio services. One common example is a licensed radio amateur that wants one radio to cover the Family Radio Service (FRS), General Mobile Radio Service (GMRS), and the 2m/70cm ham bands. Some people also want the Multi-Use Radio Service (MURS)…or maybe even marine VHF or aircraft VHF. The thinking goes that if one radio can transmit and receive on all these frequencies and that person is authorized to use those frequencies, then one radio can do it all.

This seems like a reasonable objective but the problem is that the FCC has a few rules and regulations that come into play.  This leads to an important note: I am writing about the FCC rules and regs here…you may choose to ignore them but that’s on you.

Part 97: Amateur Radio Service

First, the good news. The Amateur Radio Service, governed by FCC Part 97, has very few restrictions on the type of equipment you can use. Heck,  you can build a transceiver from parts and put it on the air. So the ham rules are not going to be a major limitation.

Part 95: FRS, GMRS and MURS

FRS, GMRS, and MURS radios are governed by FCC Part 95.  Section 95.591 says this about FRS radios:

§ 95.591 Sales of FRS combination radios prohibited.

Effective September 30, 2019, no person shall sell or offer for sale hand-held portable radio equipment capable of operating under this subpart (FRS) and under any other licensed or licensed-by-rule radio services in this chapter (devices may be authorized under this subpart with part 15 unlicensed equipment authorizations).

Section 95.1761 says this about GMRS transmitters:

(c) No GMRS transmitter will be certified for use in the GMRS if it is equipped with a frequency capability not listed in § 95.1763, unless such transmitter is also certified for use in another radio service for which the frequency is authorized and for which certification is also required. No GMRS transmitter will be certified for use in the GMRS if it is equipped with the capabilities to operate in services that do not require equipment certification, such as the Amateur Radio Service. All frequency determining circuitry (including crystals) and programming controls in each GMRS transmitter must be internal to the transmitter and must not be accessible from the exterior of the transmitter operating panel or from the exterior of the transmitter enclosure.

(d) Effective December 27, 2017, the Commission will no longer issue a grant of equipment authorization for hand-held portable unit transmitter types under both this subpart (GMRS) and subpart B of this part (FRS).

Similarly, MURS radios have this restriction (Part 95.2761):

(c) A grant of equipment certification will not be issued for MURS transmitters capable of operating under both this subpart (MURS) and under any other subparts of this chapter (except part 15).

The FCC is saying (requiring) that FRS, GMRS and MURS radios must work on their designated frequencies and nothing else. At one time, it was legal to sell a combination FRS/GMRS radio but the FCC has specifically removed that option. Part 95.1761 seems to leave an opening for a GMRS radio that is also certified for use in another radio service, but that is a very thin opening and it specifically excludes the Amateur Radio Service.

Now, why would the FCC put these restrictions in the regulations? The answer is pretty simple: these radio services are intended to be used by everyday, non-technical folks. The radios need to be simple to use and not include the capability to wander off onto any old frequency. Hence, the rules lock down the frequencies that the radios can use.

(As a side note, this regulatory approach is good for amateur radio. Imagine if FRS radios had Channel 30 set up to transmit on 146.52 MHz, with a note in the manual that says “only use this channel if you have an amateur radio license.” We would have a crapton of unlicensed operating on 2 meters.)

Part 90: Private Land Mobile Radio Services

Part 90 regulates a broad range of land mobile radio, including public service, police/fire, search and rescue, forestry, utilities, and businesses. Licensing is very specific under Part 90. A radio license will specify a particular set of frequencies allowed, specific power levels and emission types, and even the allowed operating location of the radios.

Radios designed for Part 90 are usually programmed by a radio tech to operate only those specific frequencies that a licensee is authorized to use. This results in a relatively simple operating set up with the user just selecting from the preset channels on the radio. Part 90 radios normally cover a wide range of frequencies so that the manufacturer and the radio shop can sell one radio model to any licensed user.

In many cases, these Part 90 radios cover the adjacent amateur bands, such as 2m and 70cm. (For example, the Anytone AT-D878UV is Part 90 certified and covers 140-174 MHz and 400-480 MHz.)   So this does open up the possibility of using a Part 90 radio under a Part 90 license and using it on the ham bands. A typical scenario is when a Search and Rescue member has a Part 90 radio set up to use the S&R frequency as well as the 2m/70cm amateur bands. The key to this is starting with a radio that is Part 90 certified and then programming it for the amateur band.  Of course, you need to be authorized to use the Part 90 frequency and have an amateur radio license.

Getting Creative on Radio Configuration

A few years ago, Anytone Tech tried to market the TERMN-8R VHF/UHF radio as legal for the ham bands, GMRS, MURS and Part 90 use.  An early review of this radio is here on the PD0AC blog. Basically, the radio had three distinct operating modes: GMRS, MURS, and Commercial/Normal. Initially, the FCC approved the radio but later took a closer look and canceled the authorization. The TERMN-8R is still available but without the three modes. It is marketed as a Part 90 radio that also does the amateur bands.

I recently became aware of the Anytone AT-779UV which is sold in the USA as a Part 95 GMRS radio. However, using the programming software, the radio can be configured to cover the 2m and 70cm amateur bands or a much broader range of frequencies (136-174 & 400-470 MHz). If you change the radio configuration to operate on the ham bands (or wider), the radio is no longer Part 95 certified. The configuration via software takes some knowledge and effort so it is not a mode that you can easily switch back and forth. It is really no different than other software-programmable radios.

Wrap It Up

So there you go, your dream of One Radio To Rule Them All (FRS, GMRS, MURS, and the 2m/70cm ham bands) is not going to happen. At least not legally. You can configure a radio to do this…but it will not meet FCC regulations.  However, you can configure a Part 90 radio to operate legally on Part 90 frequencies and on the amateur bands.

The post One Radio To Rule Them All (Ham, GMRS, FRS, MURS)? appeared first on The KØNR Radio Site.

Most automobiles don’t provide a lot of room for mounting ham radio transceivers. (Obviously, their design priorities are wrong!) Because of this, many ham transceivers have removable control panels that can be mounted on the dashboard and the main radio is installed somewhere else, such as under a seat.

Midland radio is doing some interesting things with micro-sized radios for the General Mobile Radio Service (GMRS). The MXT275 MicroMobile® Two-Way Radio puts all of the radio controls and the display in the handheld microphone.

Yaesu FT-8500

This radio reminded me of an old Yaesu radio, the FT-8500, which had almost all of the controls crammed onto the microphone. (Someone named the microphone “Mr. Potatohead” which seems appropriate, but I did not name it.) This radio had the display on the radio body, which seems like a limitation. At any rate, this rig was not very popular. I do not know anyone that owned one.

So the FT-8500 was not a big hit but maybe it is time for another go at a microphone-centric transceiver. I am thinking a basic 2m/70 cm FM radio could use this approach to ease the mobile installation challenge.

Simplicity in Design

You may be thinking that a GMRS radio is fundamentally simpler than a typical VHF/UHF ham transceiver.  This is true…a typical GMRS radio has 22 channels that might have options such as CTCSS tones and repeater offset. A typical ham transceiver has more frequencies, more features, and lots of settings required.

However, if you consider the typical FM transceiver setup and usage, most people set up the memories for the repeater and simplex channels they use, usually via programming software. After that, operating the radio is 99% just selecting the desired memory channel. This kind of usage lends itself to having a simpler set of controls that can be incorporated into the microphone. This approach will require a good understanding of user needs and some careful design work to create a radio that works well.

This type of radio design will probably not work for everyone. There will be hams that want every feature available all of the time.  That’s just fine. However, the microphone-centric approach may be a good fit for installation in the “other car” that doesn’t get used quite so much. Or in the case where a family member objects to having a Real Radio cluttering up the dashboard.

Using this type of radio will be a lot like using a handheld transceiver, with the addition of a microphone cable,  but no batteries or antenna cable drooping down. The Midland radio has the speaker in the radio unit but it may be better to put it in the microphone (with the option of plugging in an external speaker.)

I think this idea would well for some number of mobile radio installations. What do you think?

73 Bob K0NR

The post How About A Mic-Centric Mobile Transceiver? appeared first on The KØNR Radio Site.

We had a great time going after the W0C 10-10-10 SOTA Challenge. (See 2021 Colorado SOTA and 14er Event ) For activators, the objective was to activate 10 summits higher than 10k feet in 10 days. It turned out that some previous commitments would not allow us to do 10 days of activating, so we smushed 10 summits into 6 days. With careful choice of summits and doing multiple summits in a day, we put together a plan.

Saturday and Sunday started off with the Colorado 14er Event, so we opted to do Pikes Peak on Saturday and Mount Evans on Sunday. These are both drive-up summits, so not a lot of hiking. As previously reported, we had some good luck with 1.2 GHz from those summits. Then, on Monday we hiked Puma Peak and Little Puma, two 11k summits in South Park. On Tuesday, we did three summits on one day: Dicks Peak, 10090 and 10715. These three hikes were not particularly difficult but doing all three made for a full day.

On Wednesday, we took the Jeep up to Mosquito Pass and hiked two 13ers: Mosquito Peak and London Mountain. We had previously activated those two summits in 2018. Finally, on Thursday, we did our tenth summit with Walt/W0CP and Jerry/K0ES, one of our favorites: South Monarch Ridge. Walt and Jerry worked the HF bands while we did VHF/UHF. That was a slacker day, because we rode the tram up from Monarch Pass.

The weather was consistently fantastic, with no thunderstorms in sight. The smoke from western wildfires was thick at times and can be seen in some of the photos.

The Bands

As usual, we operated above 50 MHz, focusing on 2m, 70cm and 23cm FM operation. Most of the contacts were on 2m FM but we had significant activity on the other bands. The 1.2 GHz work was really fun: Using 1.2 GHz in the Colorado 14er Event. I made 162 contacts and Joyce made 94, for a total of 256 for the week. Not bad!

Thanks to all of our chasers and fellow activators:  AC0FT, AC0FY, AC0V, AD1CT, K0AVU, K0BEJ, K0EHR, K0ES, K0FYR, K0GPA, K0GPA, K0MGL, K0MOS, K0REW, K0SJP, K0TRD, K1DDN, K5RHD, K6TUY, K7ASB, KA4EPS, KB0KQI, KB6VHF, KC0PBR, KC3BHI, KC5CW, KD0MRC, KD0VHD, KD0YOB, KD8EQA, KE0BTX, KF0DGK, KF0FOG, KG5APL, KJ4DER, KL7GLK,
KL7IZW, KM4PEH, KM5TY, KN0MAP, KX0R, KX3DX, N0DET, N0EMU, N0IPA, N0IVN, N0KM, N1SMB, N1XCO, N8XBD, W0ADV,
W0BV, W0CP, W0JSL, W0OOD, W0RW, W1KGH, W3REM, W5IG, W6AUN, W7UM, WA0KXO, WB0JNS, WB0TNH, WZ0N

Challenge Results

The results for the W0C 10-10-10 Challenge have been posted, for both activators and chasers. Here are the Activator results:

Six activators met the challenge of doing at least 10 summits during the event. That was our goal…not pursuing the top of the list but we did want to get 10 summits done. I am fifth on the list and K0JJW came in at sixth. We had the same number of SOTA points because we did the same summits. I had more QSOs though.

It was a fun event and we were happy to be able to activate 10 summits. Fortunately, the weather was good, otherwise we might have gotten rained out on the longer days.

73 Bob K0NR

The post SOTA W0C 10-10-10 Challenge Report appeared first on The KØNR Radio Site.

Last weekend we held the Colorado 14er Event (Aug 7 and 8), the annual mountaintop event in Colorado. A group of us used this weekend as an opportunity to make 1.2 GHz (23 cm) Summits On The Air (SOTA) contacts: K0NR, K0JJW, KM4PEH, K5RHD, W0ADV, KL7IZW, W0RW, KC5RW, and K0BEJ.

Many of the 1.2 GHz operators used the Alinco  DJ-G7T triband handheld transceiver. This radio covers the 2m, 70cm and 23cm bands. The RF output on 23 cm is only 1 watt but it is the lowest-cost way of getting a signal on that band.

Pikes to Uncompahgre

On Saturday, Joyce/K0JJW and I were on Pikes Peak (W0C/FR-004) and worked Randy/K5RHD on Mount Evans (W0C/FR-003) at a distance of 97 km (60 miles). Signals were strong and we had no problem making those contacts.

We also worked David/W0ADV on Uncompahgre Peak (W0C/RG-001) at a distance of 227 km (141 miles). David used the Alinco HT driving a 16-element Comet Yagi. We had a bit more power (10 watts) from our Kenwood TM-541A transceiver, also driving a Comet Yagi antenna.  Signals were strong in both directions and these QSOs were a new personal best for both Joyce and me on 1.2 GHz.

Evans to Sunshine

On Sunday, we moved to Mount Evans and Randy/K5RHD activated Pikes Peak. We worked Randy on that peak, the reverse of the QSO on the previous day. Meanwhile, David/W0ADV was climbing two 14ers in the San Juan Mountains: Redcloud Peak (W0C/RG-002) and Sunshine Peak (W0C/RG-004). These two summits are close to each other, separated by a saddle, so it is common to climb them as a pair.

David’s route had him climbing Redcloud first and then continuing on to Sunshine, then returning to Redcloud on the way back down. We worked him on Sunshine and on the return trip over Redcloud, as he headed back to the trailhead.

We had trouble hearing David on Sunshine Peak but his signal was just strong enough that we could complete the contact. His signal was stronger from Redcloud, a surprise because the two summits are close in elevation. I expected them to be about the same in terms of signal path and strength. David reported that there was a ridge to the northeast of Sunshine that might be blocking the signal, but it was not in the way for Redcloud.

So these contacts with Sunshine Peak set a new personal best for both Joyce and me on 1.2 GHz (244 km, 152.6 miles). David clearly did the hard work, summiting two 14ers in a day. (We were on a drive-up mountain with a short hike.) Thanks, David/W0ADV!

I was very pleased with the results from the 14er weekend. Now I am wondering what’s next for us concerning 1.2 GHz. We can probably make radio contacts further out but it is going to depend on the topography of the path. We will have to do some investigation on additional summits to try.

73 Bob K0NR

The post Using 1.2 GHz in the Colorado 14er Event appeared first on The KØNR Radio Site.

Lately, I’ve been talking with people in search of basic radio communications for their friends or family. They end up talking to me because someone steered them to ham radio as a solution and I teach ham radio license classes. Of course, I am happy to pull them into the wonderful ham radio world but sometimes the General Mobile Radio Service (GMRS) might be a better way of meeting their needs.

I have a GMRS license and have written about it. See GMRS: The Other UHF Band.  GMRS is a good fit for local communications, perhaps just using simplex or with repeaters, if available in your area.  FCC regulations (Part 95) require you to have a license (and pay a fee) to use GMRS. Unlike ham radio, the license does not require you to pass an exam and the license is valid for you and your family members.

Common Uses

GMRS works well for family communication “around town” or some local area. Depending on the type of equipment used, simplex range of 10 or 15 miles is achievable, maybe more. The use of repeaters can extend this a lot further. You might even decide to put a GMRS repeater on the air, which is not too difficult of a project.

Another common use of GMRS is when a group is traveling down the highway in multiple vehicles. Yes, you might be able to just use your mobile phone to stay in touch but a two-way radio may be a better solution (especially when mobile phone coverage is poor or non-existent). Many off-road vehicle clubs have discovered GMRS and use it for communicating during trail rides.

GMRS is also a great tool for outdoor activities such as camping, hunting, hiking and skiing. It is a handy way of staying in touch with your tribe, while not depending on the mobile phone network.

GMRS Is Not FRS

GMRS often gets confused with the Family Radio Service (FRS). They both include the use of inexpensive, low-power handheld radios and they share many of the same frequencies. When the FCC authorized FRS, GMRS was already an established radio service and it squeezed FRS into the same band. FRS radios were limited to lower output power, so many manufacturers decided to offer combination FRS/GMRS radios, which operated at higher power levels. The user was supposed to obtain a GMRS license to use this type of radio but most people didn’t bother with it. (Most people probably didn’t even know of the requirement.)  The FCC also specified 2.5 kHz (half deviation) FM for the FRS radios on the same channels as the existing 5 kHz deviation GMRS radios. Intermingling an unlicensed radio service with a licensed service was probably not a wise move. In general, the FCC regulations caused a lot of confusion between the two services.

In 2017, the FCC adopted a major revision to the GMRS rules to clean up some of the problems with the service. In particular, the regulations now prohibit the sale of combination FRS/GMRS radios. A great idea but a bit too late in the game.

The GMRS rules are pretty easy to understand, so take a look here: FCC Part 95 – Personal Radio Services

Equipment

There are basic handheld transceivers for GMRS. They look and act a lot like the FRS radios that are widely available, but GMRS can provide more capability. An advanced handheld radio will have support for using repeaters (transmit offset) and higher power (up to 5 watts).

To dramatically improve the radio range, you can use GMRS mobile and base stations that can run even more power, up to 50 watts. More importantly, you can use external antennas on your vehicle or your house. These can make a huge difference in performance. (FRS is limited to handheld transceivers and the permanently-attached rubber duck antenna.)

For radio amateurs, this should all sound pretty familiar. GMRS looks and acts a lot like an FM transceiver on the 440 MHz (70 cm) band. It is a great alternative for local radio communications for people not interested in a technical hobby such as amateur radio.

The post GMRS: Basic Radio Communications appeared first on The KØNR Radio Site.

The Summits On The Air (SOTA) program originated in the United Kingdom but has propagated to most countries around the world. The program came to Colorado on May 1st, 2010 with Steve/WGØAT sending a CQ from Mount Herman, just west of Monument. Today, the SOTA program in Colorado (called WØC-SOTA) is very active with roughly 180 activators that operate from Colorado summits.

To celebrate our 10th Anniversary, WØC-SOTA is organizing a 10-10-10 Event with a challenge for Activators and Chasers alike. (Activators operate from summits, Chasers try to contact them.)

Activator challenge: Activate 10 (or more) 10K feet (or higher) summits (in Colorado/WØC) within 10 days.

Chaser challenge: Chase Activators on 10 different (or more) qualifying WØC summits (10K or higher) within the 10 days.

Event Date: We will kick-off the event in conjunction with the Colorado 14er event on August 7th, 2021 and conclude on August 16th.

Everybody is invited to participate, either as an Activator or a Chaser. Block off these days in your calendar now and start planning for how you can participate. Feel free to operate as much or as little as you would like. It is all about having fun messing around with radios. Any HF, VHF or UHF band can be used for making SOTA contacts, with the most popular ones being 40m (CW & SSB), 20m (CW & SSB) and 2m (FM).

Note that the recommended 2m FM frequencies for the 14er event have changed to:

146.580 FM   North America Adventure Frequency
146.550 FM    Simplex Alternate
146.490 FM    Simplex Alternate
146.520 FM    National 2m FM Calling Frequency
(as needed, please don’t hog the calling frequency)

There will be a leaderboard on the W0C-SOTA website showing all participants who meet one of the challenges. More details will be announced on the WØC-SOTA Website as soon as they are hashed out.

For more information on the SOTA program in general, see the worldwide SOTA website.

Full Disclosure: May 1 is actually the 11th Anniversary, but the COVID-19 Pandemic interfered in 2020, so we are catching up.

The post 2021 Colorado SOTA and 14er Event appeared first on The KØNR Radio Site.

A perpetual ham radio question is always which antenna is best? I have several different antennas and antenna configurations for working VHF SOTA and decided to do some comparisons.

To test out some of our 2m SOTA antennas, Joyce/K0JJW and I went to Eagle Rock (W0C/SP-113) with an elevation of 9710 feet. I did the radio operating while Joyce collected the data. Eagle Rock pokes up out of South Park, which is a broad, high plain in central Colorado. This summit is kind of “mid-range” for Colorado…not as high as the 14ers but with significant elevation and prominence (~500 feet). It also was close enough to a number of SOTA chasers so I could get some good S-meter readings to compare antennas. On the summit, there is a clear 360-degree horizon, dropping off quickly in all directions.

Antennas Tested

Antenna A is our GO-TO antenna for VHF SOTA is the 3-element Yagi from Arrow Antenna, handheld so the boom is about 5 feet off the ground. Arrow does not specify the gain on this antenna but it has been measured at the Central States VHF Society conference to be ~6dBd.

Antenna B is a dual-band J-pole manufactured by N9TAX, supported by a telescoping fishing pole commonly used by SOTA activators. A J-pole has a halfwave radiator, so the gain is about 0 dBd, the same as a dipole.

Antenna C is an RH770 telescopic antenna mounted on a monopod, using a bracket that I made. See VHF/UHF Omni Antenna for SOTA Use. This antenna is a halfwave on 2 meters, so again we’d expect the gain to be ~0 dBd. The antenna is supported by a monopod which I usually just stick into the ground or strap to a bush.

The three antennas being tested were driven with short coaxial cables fitting with BNC connectors for easy changes. The transceiver was a Yaesu FT-90 powered by a small Bioenno battery.

Chaser Stations

I put the word out that I’d be doing some antenna comparisons and five chasers showed up to assist. (There were are few other chasers that were too close to Eagle Rock such that the S meter readings would have all been “full scale” and not useful.)

Most of these stations were not line-of-sight because there is mountainous terrain blocking the direct path. This makes for a good test because this is often the situation when doing SOTA activations in Colorado. We often have mountains in the way, even on the high summits. Said another way, line of sight contacts are easy-peasy and the antenna performance is not critical. Getting the signal to punch through or around mountains is when the antenna really matters.

WZ0N was line-of-sight from Eagle Rock. KN0MAP was not line-of-sight and he had his Yagi antenna pointed at Pikes Peak (away from Eagle Rock). This is a common technique on VHF…point at a high summit and hope you get enough of a reflection to make the contact. The chasers are listed below.

Signal Reports

Your typical FM VHF/UHF radio doesn’t have a real S meter, just a bar graph display, so we worked in terms of “number of bars”. This does not give us a calibrated measurement but it does provide for a valid comparison. A signal that is 5 bars is stronger than one with 3 bars, but we don’t really know how much better (in terms of dB or S units). We recorded meter readings at both ends of the radio contact. My Yaesu FT-90 meter has 7 bars as full scale. On transmit, I was running the FT-90 at 20 watts.

A quick look at the Antenna A column shows that the Yagi had consistently better signal levels than the other two antennas.  For each contact, I did point the Yagi in the direction of the strongest signal, taking care to maximize the signal. This is an advantage and disadvantage…you have to point the antenna but you do get a stronger signal.

The two omnidirectional antennas (B and C) did not require pointing and they performed about the same. My impression is that Antenna B had slightly better overall performance based on listening to the FM noise. But note that the AD0WB readings were slightly better with Antenna C.

As is very common in the mountains, we experienced multipath distortion. This occurs when the signal takes multiple paths to the other station (reflecting off mountains) and then recombines at the receiver creating distortion and variation in signal level. Small changes in antenna position can cause a change in the signal level and amount of distortion. Multipath distortion was much more noticeable on the omnidirectional antennas. The Yagi antenna exhibited multipath but at a much-reduced level. This is a well-known phenomenon: directional antennas reduce multipath effects.

Another factor that I believe is important is that Eagle Rock pokes up quite dramatically compared to the surrounding terrain. Compare this to a large, flat summit that could shadow your signal at some angle of radiation. Antenna height relative to the immediate summit terrain might be more important. Another factor is that Eagle Rock is pretty much granite and not very conductive. So there is not much difference between having an antenna 5 feet off the ground (rock) vs putting it up on a mast.

Previously, I wrote about Charlie/NJ7V’s video that compared a roll-up J-pole with a 3-element Arrow Yagi antenna on two meters. Charlie’s results were a bit different, indicating that the J-pole was about the same or in some cases better than the Yagi.

Conclusions

The Yagi antenna clearly outperformed the two other antennas. So the Arrow 2m Yagi will continue to be our antenna of choice.

The paths to K0MGL and KN0MAP were the most difficult and this is where the Yagi performance really came through. For KN0MAP, we were both pointed at Pikes Peak and working off the reflection. This method worked well with the Yagi but had significant signal loss such that the omni antennas could not make it. Working K0MGL on the omni antennas was not much better but we did squeak out two contacts.

I was a bit surprised that Antenna B did not do significantly better than Antenna C, due to antenna height. This all seems to indicate that once you are on top of a rocky SOTA summit, additional antenna height does not matter. (It would be interesting to do some experiments with the same antenna set at different heights.) I do like having an omni antenna available so that we can monitor in all directions while eating lunch, etc. If we only have the Yagi at lunch time, it is usually laying on the ground or stuck into a tree, certainly not effective in all directions. Antenna C is so easy to deploy, it will probably be my preferred omnidirectional antenna.

This is just one test and one set of results. It will be interesting to do some further comparisons from other locations. Thanks to the chasers for assisting with these tests.

73 Bob K0NR

Test data in Excel spreadsheet:  Antenna comparisons – 2m FM Eagle Rock

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