Author Topic: My other hobby, ham radio  (Read 14659 times)

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Mary B

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My other hobby, ham radio
« on: December 15, 2015, 05:01:52 PM »
I have been working on getting this tower done for a month now. Lot of cabling, building antennas, getting things mounted, tested and finally getting the tower up and running. Tower is a very heavy duty 32 foot crank up. The H frame is 2"OD .25 wall 6061 aluminum tubing. Antennas are 20 feet long and all cable is hardline which is a pain to work with!



Initial testing over the weekend was very very good! Worked a bunch of meteor scatter contacts(bounce signals off the ionized meteor trails) with the longest 1100 miles. Also tested the tracking on a couple of satellites and it worked well!

Rotor does azimuth and elevation so I can point at the moon. Main reason I built this antenna system is moonbounce communications where I use the moon as a passive reflector. Frequency is 144mhz(2 meter ham band).

Also put up a 29 foot tower for 6 meters and 70 cm(50mhz and 432mhz)



Been a lot of work this summer between the new garage and the tower rigging!

DamonHD

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Re: My other hobby, ham radio
« Reply #1 on: December 15, 2015, 05:37:20 PM »
Does 433MHz ISM band stuff ever make it across from Europe?  I don't know what the propagation modes might be, and what local sources you might have...

Rgds

Damon

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Re: My other hobby, ham radio
« Reply #2 on: December 15, 2015, 11:18:53 PM »
You can seriously communicate with Earth-bound stations by bouncing off the moon?!
OMG... googled it:  250 dB losses from sender to receiver. 
"We choose to radio the moon, not because it's easy, but because it is hard."

Stop before you infect me.  I have enough hobbies!
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

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hiker

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Re: My other hobby, ham radio
« Reply #3 on: December 16, 2015, 11:22:12 AM »
My old sideband cb...was fun to mess with in the winter months...had a 17 foot ground plane antenna. Reached out to the lower 48--Australia and a lot of other countries as well..just a stock setup..whip antenna on the truck as well....cb radios kinda died off here..except for the far north...fun stuff...just might have to fire up the old rig..
WILD in ALASKA

Mary B

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Re: My other hobby, ham radio
« Reply #4 on: December 19, 2015, 04:07:31 PM »
Seems this was one of the lost posts...  no biggie!

the ISM band stuff is extremely low power and while it may travel a couple hundred miles during troposheric ducting it is not capable of being heard off the moon! Not with current receive technology anyway! ISM stuff is .01 watts! I am using 1,000 watts on 2 meters to bounce a signal off the moon! Guys on 432mhz eme use maximum legal limit of 1,500 watts and some break the laws and push it way past that!


Does 433MHz ISM band stuff ever make it across from Europe?  I don't know what the propagation modes might be, and what local sources you might have...

Rgds

Damon

Mary B

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Re: My other hobby, ham radio
« Reply #5 on: December 19, 2015, 04:08:54 PM »
Right now about all you will get on CB is some E-skip and that season is ending. With the sunspot cycle winding down F2 propagation is becoming rare on the upper bands.

Mary B

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Re: My other hobby, ham radio
« Reply #6 on: December 19, 2015, 04:09:55 PM »
Moonbounce is a lot of tinkering, a lot of building, technical challenges etc and that is why I do it!

You can seriously communicate with Earth-bound stations by bouncing off the moon?!
OMG... googled it:  250 dB losses from sender to receiver. 
"We choose to radio the moon, not because it's easy, but because it is hard."

Stop before you infect me.  I have enough hobbies!

ChrisOlson

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Re: My other hobby, ham radio
« Reply #7 on: December 21, 2015, 09:33:15 AM »
Moonbounce is a lot of tinkering, a lot of building, technical challenges etc and that is why I do it!

EME is not something you just do and it happens by chance.  I got three successful EME's in September on 6 meters working in partnership with a station in Norway.  We used JT9 on wsjtx software, I used a nine-element (all elements driven) dipole array with three elements at 1/4 wave spacing front to rear driven successively at 90 degrees out of phase, and stacked three high at 5/8 wave stacking.  The station in Norway used two 9 element yagi's stacked at 5/8 wave.  We ran about 800 watts of power.

My dipole array is useless for other normal communications because the front lobe off it is like a flashlight beam.  If I point it at you - only a few degrees off and the signal misses you.  The beam is so tight it will just about set trees on fire on the horizon.  Like Mary said, it takes a lot of tinkering and building - I spent most of the summer with the analyzer adjusting phasing lines, phase spacing and stacking to tune up the array.  I worked with another station about 110 miles away in Rhinelander for the tuneup.  And then when the day comes the moon has to be visible at both locations (which means only at moonrise into Europe from the US) and weeks worth of preparation and work last about one minute each way for each successful EME contact.  And even then it takes a lot of luck because the surface of the moon is not all that smooth and tends to scatter your reflected signal.

We were using only a 20 Hz pass filter on the receiver front ends for a 16 Hz wide signal.  And the timing has be precise, +/-60 ms, sync'd with an atomic clock between the two stations.  Almost 100% of the amateurs doing EME on 6 are using linux to drive the rig because Windows isn't accurate enough and does not use the Unix Epoch clock for timing.  Few people are doing EME on 6 because of the path loss and technical difficulties.  But it was still a lot of fun.  Our next attempt will be in February, working with the same station in Norway, and in concert with another station only about 4 miles from me that has built an experimental 6m wireframe parabolic reflector.

Mary B

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Re: My other hobby, ham radio
« Reply #8 on: December 21, 2015, 04:41:00 PM »
Hard part on 6 is engineering the support structure for such large antennas. I had stacked 5 element beams on 6 on a 17 foot mast... mast finally failed in one of my many windstorms. Bent 30 degrees. Luckily that tower also cranked down and tilted over so I could salvage the antennas. Since it was a rotating tower I moved one of the antennas to a lower section but that out it at 21 feet so not as effective. That tower finally showed enough wear that I had to retire it. Where it rotated was steel on steel and it had worn a deep groove...

W7GJ's 6 meter eme array... lots of engineering and I do believe it failed recently...


ChrisOlson

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Re: My other hobby, ham radio
« Reply #9 on: December 24, 2015, 12:00:39 AM »
That's why I went with the dipoles instead of yagi's.  Stack up three elements on a driven array at 1/4 wave spacing, with each element driven 90 degrees out-of-phase in succession and the f/b ratio is VERY impressive.  Another station only 5 miles away transmitting at 100 watts can't be heard on the back side of a three-element driven array.  The phase cancellation, once tuned to perfection, is 100%.  And the whole thing is only 10 feet long, front to back.  But it's 23 feet high once you add two more three element driven arrays at 5/8 wave stacking height to get the azimuth angle down tight.

You can't just turn that array - it has to have azimuth tracking as well.  And to get maximum ground gain on the ground plane radials laid out in front it, pointing east, the bottom elements have to be precisely 19.6 feet from ground.  So from ground level the whole thing is 43 feet high.  I welded an old satellite tracker to the end of a 20 foot long piece of 4" x 11ga pipe and set it in concrete.

Phased all-driven arrays are very hard to tune.  I used 75 ohm RG59 for the phasing lines, feed the junction box with open wire parallel feeder, and you find variations in VF on lengths from the same roll of cable.  And then you get it perfectly tuned, the temperature goes down, the Velocity Factor goes up and it's out of tune again.  In February when we make our first set of attempts for the new year I'm sure I'll be out there in 20 below with the analyzer tuning up spacing on the elements to match the VF of the phasing lines at sub-zero temps.

And all that work for about one minute of glory that there's only about a 10% chance of being successful at.

The other station I'm working with that built the wireframe reflector, and I, are going to try simpler EME, station to station when the moon is a little higher in the sky.  I can only tilt my array 30 degrees so even that has a pretty narrow window of opportunity.

But it's still fun, and a nice departure from working HF all the time.

When I go over to Steve's place sometime I'll take a photo of his wireframe reflector he built.  It's pretty big, made mostly out of 2/4's for the framework to hold the dish movement.  And he made the framwork for the dish itself out of light angle and 3/16" steel rod with several microwave screen reflectors laid in it.  It's a pretty impressive antenna, made mostly of parts gotten from Menards, except for the microwave reflector screens which he got salvage off a microwave tower someplace.  Took him all summer to build it.

Merry Christmas!

tanner0441

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Re: My other hobby, ham radio
« Reply #10 on: December 24, 2015, 02:01:53 PM »
Hi

I did post previously but my post and Mary's reply seem to have disappeared. However if you think that your beam had a very narrow beam width Chris, try 3cms with an Andrew's four foot prime focus dish. it was the only dish I had at the time. According to the spec it was a quarter of a degree. The same as the transmitter on the satellite transmitters, at over 44,000 miles that is OK, at a few tens of miles you're really pleased you included a panning signal in the design.

I still prefer VHF/UHF to HF but I live in a VHF black hole. If ever this part of North Wales need an enema this is where they will put the funnel, RF wise.

I like your idea though Chris of phased dipoles, and if i make a phasing harness I bury the joints in hot melt glue, and spray them with freezer to stop it running off.


Brian

Mary B

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Re: My other hobby, ham radio
« Reply #11 on: December 24, 2015, 06:19:39 PM »
I would never keep something like that up in the winds out here on the prairie! I have a 10 foot dish mounted on 6 feet of rohn 25... tower section bent and it stripped a heavy duty gear reducer I used for az drive.

Been thinking about 10ghz eme. Use a 4 foot offset dish like you have. Be a lot easier to keep up in the wind!

tanner0441

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Re: My other hobby, ham radio
« Reply #12 on: December 25, 2015, 11:30:04 AM »
Hi

If you want a lot of gain on a dish prime focus or offset look at one where the LNB mounts through the dish and there is a hyperbolic reflector, the signal hits the dish and focuses onto the hyperbolic unit and back into the LNB.
I think Echo star make them for DBS systems, the gain is a lot higher than he basic dish.

If you want an interesting evening try the maths for hyperbolic curves,

Brian

Mary B

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Re: My other hobby, ham radio
« Reply #13 on: December 25, 2015, 02:45:41 PM »
Pass on the math!

I would go offset dish, less ground noise picked up by the feed due to spillover.

tanner0441

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Re: My other hobby, ham radio
« Reply #14 on: December 27, 2015, 02:23:18 PM »
Hi

If you want a quiet dish then you want a very shallow dish they have a much lower G/T (gain/temperature) figure. The problem with dishes is if they deviate from a true parabaloid by more than 1/80th of a wavelength then they will squint and fire lobes all over the place, and on 3cms if you use a mesh material the holes can't be bigger than 2.5 to 3mm or again you will get lobes of the hole edges.
 
I have a phased printed array from a marine radar setup. It has 72 circular quarter wave pads in 24 by 3 on a GRP substrate, with a flat plate reflector they have a beam width of 6deg horizontal and 27deg vertical beam width. this can be narrowed down by firing it into an orange peel reflector or put barn doors on it like a horn.



Brian

Mary B

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Re: My other hobby, ham radio
« Reply #15 on: December 27, 2015, 03:55:57 PM »
4' offset fiberglass Ku band dishes are dirt cheap, can get one shipped for about $150... haven't found a 6 footer which would be better but I haven't searched hard. Long term project anyway. Need to collect parts, transverter, amplifier (30 watts at 10ghz is EXPENSIVE!), feed, dish, mount, design the az/el parts...

ChrisOlson

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Re: My other hobby, ham radio
« Reply #16 on: December 31, 2015, 07:11:32 PM »
I'm not really into dishes that much myself, nor UHF.  I decided to go with the dipoles because they're easier to tilt than a stacked array with like a couple 7 or 9 element yagi's in it, and has way more gain.  6 meters is as high as I go in frequency here - don't even own a 2m radio, nor have any use for one.

I got the idea from the Russian Woodpecker radar arrays that used to come in on 20 and 40 meters back in the late 70's and 80's.  The Russian Woodpecker was really the Duga directional radar arrays that operated on shortwave, and they were built totally with driven dipoles fed with ladder line.  10 MW of effective radiated power in the direction the arrays were facing.


Mary B

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Re: My other hobby, ham radio
« Reply #17 on: January 01, 2016, 04:44:48 PM »
Yeah the woodpecker was a great band is open indicator! Annoying but it did tell you what the MUF was! They used to run all the way up to 30mhz at times.

I like VHF+ because I can tinker. I just ordered a noise figure meter for tweaking preamps. Will let me build and sell a few, do some repairs etc. Need to find a noise source for it yet or build one. Lot of small machining etc for preamps that I can do with simple equipment like my drill press. Plus the antennas are small!

 Tinkering with HF stuff takes a lot of space for antennas and I don't have it.

madlabs

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Re: My other hobby, ham radio
« Reply #18 on: January 01, 2016, 08:27:36 PM »
Mary, I'm with ya. VHF/UHF is cheap, small and fun to play with. My quad stack of 440 mHz Yagi's is just so darn cute! Cost almost nothing to build and took an afternoon. My buddy has a similar setup and we can chat on a few 10's of mW's. Great for chewing the rag while noodling around on the HF bands. Also love the 2M band for local comms. We have very poor cell coverage but great 2M, either simplex from home or via repeaters. Nice to know the YL can reach out if she needs help or I forget to ask her to get something from town. An between several linked repeater system I can talk to her well out of the area too.

The YL is testing for her General ticket (and I am going for Extra) in a couple of weeks. The we can put a dc to daylight rig in her car!

Jonathan - KK6RPX


tanner0441

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Re: My other hobby, ham radio
« Reply #19 on: January 02, 2016, 09:10:00 AM »
Hi

While we're reminiscing on the Woodpecker another bane in the life of the top band operator was Loran wandering slowly around the top of the band, and I doubt you suffered with them in the US, was the Fishing Trawlers in the north sea who would come down below 2 Mhz if it was a bit noisy where they should have been, with the obligatory flowery language, where everyone was of dubious lineage and intelligence that didn't work for the same company they did.

You were OK in between them though because Power Line Transmitters and switched mode power supplies hadn't been invented, so apart from shot noise from the resistors life was quiet, and transistors were limited to audio and similar frequencies, and did anyone have problems with the 78 series regulators that whistled happily around 60 Mhz.

Happy daze. (not a typo)

Brian.

ChrisOlson

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Re: My other hobby, ham radio
« Reply #20 on: January 04, 2016, 11:42:25 AM »
While we're reminiscing on the Woodpecker another bane in the life of the top band operator was Loran wandering slowly around the top of the band

Oh no, we lost 1850, 1900 and 1950 kHz on 160 meters to Loran-C.  And were prohibited from causing interference to the service (secondary use).  We got the band back when they discontinued it in 2010.

Every year the FCC puts frequency spectrum on the auction block to be sold to the highest bidder.  2m amateur has been eyed seriously by VHF low-band TV broadcasters interested in expanding their channel range.  440 MHz is already secondary use by amateur radio because of cable TV bought part of the spectrum.  Etc.

2 meters today is the biggest waste of frequency spectrum in ham radio.  The biggest portion of the band tied up with repeater pairs - and repeaters that mostly sit silent day after day until some ARES/RACES club runs their weekly "nothing new to report here" 2m net on them.  Otherwise, you can drive across the country and call on 2 meters on different repeaters as you go, and never get an answer anymore.  This does not go unnoticed by the FCC.  ARRL tries to make out like it's so important for ARES/RACES clubs for emergency communications, which is basically a joke.  When an actual disaster hits and infrastructure is down, the ARES/RACES clubs are running around in important-looking orange and yellow coats calling to dead repeaters on HT's that don't work anymore because the repeaters are all down.  That's when the NTS on HF kicks in, which has been the backbone of emergency communications in ham radio since 1936.  The ARRL jumped into it in 1949 and tried to act big important.  But the ARRL is a joke too.

madlabs

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Re: My other hobby, ham radio
« Reply #21 on: January 04, 2016, 12:23:07 PM »
I mostly agree with that assessment of 2m. Relying on repeaters isn't a good idea. Not much going on. There are some good uses for 2m in disasters though, 2m got evacuation orders to a neighborhood in Lake county last year when the fires were bad and EMS was stretched. There were other instances in that incident as well, fire reports from areas with no phone, welfare checks and so on. 2M was hopping with news and activity during the fire season. Some friends and I are setting up a 2m email system as well, repeaters optional, going out through HF or satellite. So there are a few things that 2m is great for but I think it is for individuals more than EMS.

But I totally agree that I don't see effective organized response on 2M and don't see how it can be done. Individual hams will do just as well at passing information and getting help.

Jonathan

tanner0441

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Re: My other hobby, ham radio
« Reply #22 on: January 04, 2016, 02:29:49 PM »
Hi

We don't have the distances you have in the US so 2M here for emergency comms does work, I was a member of our RAYNET some years ago when the ambulances went on strike and covered the radio requirements of the St. John ambulance service that covered it.

The thing that holds no interest for me is this D-Star where the repeaters link via the internet, you hear someone who lives a couple of miles from the repeater talking to someone in the US who also lives a couple of miles from his repeater, then comment on how clear it is and working across the Pond on 2 M. Don't seem to be able to grasp it is VOIP not DX.

Brian.

ChrisOlson

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Re: My other hobby, ham radio
« Reply #23 on: January 04, 2016, 03:07:41 PM »
The thing that holds no interest for me is this D-Star where the repeaters link via the internet, you hear someone who lives a couple of miles from the repeater talking to someone in the US who also lives a couple of miles from his repeater, then comment on how clear it is and working across the Pond on 2 M. Don't seem to be able to grasp it is VOIP not DX.

Yeah, D-Star I think was ICOM's idea.  And then Yaesu came up with their own implementation.  So you got no standarization of digital technology.  One club buys an ICOM repeater and then all their gear don't work with the next club that bought a Yaesu System Fusion unit.

I just throw my hands in the air and use radios that don't need no repeaters.  Actually, the serious VHF operators don't hang out on repeaters much anyway.  They're working weak signal stuff like Mary likes to do.  It's just the fact that the VHF band plans are so screwed up with FM repeater pairs tying up big bandwidth that could be put to much better use.  2 meters used to be a lively active band back in the 70's when all there was was AM and SSB.  Then all these FM repeaters started popping up all over the place and it killed it to the point where 2 meters is just a glimmer of what it was 40 years ago.  ARRL keeps it up and 2 meters will be sold to the highest bidder just like 11 meters and 440 was.

PNW_Steve

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Re: My other hobby, ham radio
« Reply #24 on: February 17, 2016, 09:55:38 PM »
You can seriously communicate with Earth-bound stations by bouncing off the moon?!
OMG... googled it:  250 dB losses from sender to receiver. 
"We choose to radio the moon, not because it's easy, but because it is hard."

Stop before you infect me.  I have enough hobbies!

:) Gotta love it!!

While cell phones and the Internet have nearly killed the Ham Radio hobby there are still people out there having a ball with it.

In 1991 (I think...) we accomplished moon bounce on 2m using something outrageous like a 30+ element HANDHELD yagi. The propagation delay was such that we sent CQ and then were able to pause then hear our own call return. There was a write up about it in the Orange County Register. It was a demonstration that was part of one of Gordo's Ham classes (WB6NOA).


PNW_Steve

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Re: My other hobby, ham radio
« Reply #25 on: February 17, 2016, 10:22:04 PM »

Mary,

It does me good to see "real operators"  do still exist. When I got started in the hobby we made fun of people that got their license and then went to the Ham store and bought everything readymade. We called them "appliance operators". We figured that if you didn't homebrew at least some of your gear then you were not really a Ham.

I have been out of touch for a while. I went full time in my RV on the road and never managed to pull together a mobile HF setup. I was active on VHF/UHF until the no class technician license came to be. At that time the repeaters that I frequented became overrun with folks that behaved like they were CB'ers. I let my license lapse. I did finally get licensed again and found that I lived in a County with only one other Ham and I had no HF rig. 

You have inspired me... I am going to dig my gear out of the shed and get back on the air.

Thank you!!

ChrisOlson

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Re: My other hobby, ham radio
« Reply #26 on: February 18, 2016, 09:39:22 AM »

When I got started in the hobby we made fun of people that got their license and then went to the Ham store and bought everything readymade. We called them "appliance operators". We figured that if you didn't homebrew at least some of your gear then you were not really a Ham.

Pretty much the other way around now.  The hams that build everything from scratch get made fun of by the appliance operators because the appliance operators think their stuff is so much better. They hang out on internet forums like The Zed with big signatures listing all their store-bought stuff, instead of hanging out on the air.  They work contests to fill up electronic logs over the internet, don't keep paper station logs, and don't send paper QSL's anymore to confirm a contact. They make fun of the people on 75 meters that still enjoy the good old ragchew nets. In fact, they don't even call 3,900-4,000 kHz 75 meters - they call it 80 meters now, when 80 is 3,500-3,900 kHz to the old hams.  They prefer impersonal computer-controlled digital contact modes like JT65 to fill up electronic logs instead of working CW or other modes that actually require some communications skills. One foreign station comes in on 20 meters and you got a big pileup with 500 or more stations all calling at once to make a 30 second contact and get an entry in their internet logbook.  They operate VoIP on internet repeater nodes instead of HF.  They send each other text messages on cell phones to arrange a 2m repeater QSO, or otherwise are only on during "drive time".  That would describe about 95% of today's operators.  They have become internet and cell phone operators posing as radio operators.

You'll find us "old timers" groups that still operate the old way on 160m, and in the Extra and Advanced portions of the HF bands where the appliance and internet operators can't come and spoil it.  We still work CW with a straight key or paddle and message each other worldwide on 40 meters, 7091.3 KHz, with RTTY, PSK or MFSK instead of arranging QSO's or contests on the internet. We still use 11 meter SSB for local communications and our non-ham wives consider it more convenient to grab the mic and give a call on the radio instead of using a cell phone.  But it is a quite small group anymore.

It is quite amazing - one of the General class appliance operators from the local club caught some PSK-125R messaging on 40 meters one day between me and another station when I was sending a schematic of a circuit with Flwrap.  I don't actually belong to that club but I do run a 6m net for them.  Anyway, this guy called me on my cell phone and told me that I haven't kept up with modern technology in ham radio.  He said people use cell phones and internet, and PSK on radio is for making contacts.  He does not even understand that there is still a small group of us that communicate by radio only.  Doesn't have even the faintest grasp of the concept.  Their club identity is their website, all their communications are done with their email reflector or cell phone text messages.  They even send out a cell phone text message reminder for everybody to jump on their weekly 2m repeater check-in net or nobody would show up on the radio.

If you've been "out of touch" for awhile you may be horrified at what it has become when you get back on the air.