quote:

Originally posted by ltz400:
if you wish to understand antennas study RF propagation.

I remember sitting in an electromagnetic fields and waves class, looking at all of the Greek letter variables in the math written on the board, wondering if the professor was really just writing offensive messages in Greek. Class was kinda rough.

The tool linked earlier to determine Line of Sight is likely useful, but for a situation with mobile users I'll plug SPLAT! again. Here's an example of SPLAT's output:



Caption for this pic: SPLAT! displays the line-of-sight coverage areas of four UHF-FM repeaters that are part of the W2NJR linked repeater system in New Jersey. Individual as well as mutual areas of coverage are clearly visible in this thumbnail image. Full resolution of this image is 3600x3600 pixels.

quote:

Originally posted by shikemd:

quote:

Originally posted by ltz400:
if you wish to understand antennas study RF propagation.

I remember sitting in an electromagnetic fields and waves class, looking at all of the Greek letter variables in the math written on the board, wondering if the professor was really just writing offensive messages in Greek. Class was kinda rough.

The tool linked earlier to determine Line of Sight is likely useful, but for a situation with mobile users I'll plug SPLAT! again. Here's an example of SPLAT's output:



Caption for this pic: SPLAT! displays the line-of-sight coverage areas of four UHF-FM repeaters that are part of the W2NJR linked repeater system in New Jersey. Individual as well as mutual areas of coverage are clearly visible in this thumbnail image. Full resolution of this image is 3600x3600 pixels.

That looks like a great tool as well, and I missed it the first time. I'll have to play with it over the weekend. Thank you!

quote:

Originally posted by shikemd:
The tool linked earlier to determine Line of Sight is likely useful, but for a situation with mobile users I'll plug SPLAT! again.

I can't seem to make the software work on my Mac, is there some trick to it?

Not GMRS so I didn't want to add to the other thread but this is a lot a radio for the price. Back in stock it seems. Videos on firmware flashing but I ain't quite there yet.

QUANSHENG UVK5(8) AM/FM/DTMF walkie Talkie 200Three Frequency Receiving walkie Talkie NOAA Weather Forecast, with Flash Replication Frequency Tpye-C LCD Display for Hiking Camping Trip Two-Way Radio https://a.co/d/4Evamxp

quote:

Originally posted by ltz400:

quote:

Originally posted by shikemd:
The tool linked earlier to determine Line of Sight is likely useful, but for a situation with mobile users I'll plug SPLAT! again.

I can't seem to make the software work on my Mac, is there some trick to it?

I'm not familiar at all with Mac OS as I've only used SPLAT on Linux and Windows. I would suggest looking into setting up a Linux virtual machine on your Mac. Command line only for the VM as you'll be able to view any output on the host Mac OS. Output is text, KML, and image files.

Some pitfalls:

• If you run a coverage plot and it's done in 2 seconds, you probably didn't feed it terrain files
  
• Make sure the resolution of the terrain files is as prescribed (i.e. 1 arc second for high def and 3 arc second for regular def
  
• I highly recommend the KML output for importation of coverage imagery into Google Earth. Then you won't have to bother with city location files, cartographic boundary files, etc. that just add visual reference to the output. Google Earth already has way better visual references built in.
  
• For the QTH files lat/lon is North America centric (cuz 'Merica). That is, north latitude is positive, and west longitude is positive. If you're on the other side of the equator or prime meridian, pay attention to sign
  
• Do some reading on the model inputs that might look like they require a PhD in physics. Things like radio climate and polarization. You probably don't have to worry about it too much so don't be scared off.
  
• Remember: all models are wrong; some models are useful
  
• Read the user guide
  
• Also, read the user guide
  

Some things to consider in this video. Radio communications are problematic in emergencies. As this gent points out, repeater traffic would be off the scale in a disaster, and this assumes that these repeaters would even be powered in an emergency.

Also, the vagaries and inconsistencies of RF propagation, for a myriad of reasons, which makes such communications tend toward something akin to black magic are inescapable.

Its not my intent to discourage anyone, and I'm sure that some of our more experienced radio people will disagree with some of the things this guy says, but hear him out.

quote:

Originally posted by parabellum:
As this gent points out, repeater traffic would be off the scale in a disaster, and this assumes that these repeaters would even be powered in an emergency.

The above is why awhile back, I decided to try to come up with a GMRS system to communicate with members of my family (and a few friends) without depending on repeaters. Just simplex comms, radio to radio. To completely depend on a stranger's infrastructure during a disaster or SHTF event would be ill advised. My biggest hurdle is to reach my son who is 20+ miles away as the crow flies in DFW. As pointed out in another forum, the only way I'm going to know if my setup (and my son's) will work, given terrain, antenna height, etc., is to buy the gear and try it.

quote:

Originally posted by ltz400:
Imagine a very wide lazy V shaped pattern and compare it to a very sharp V shaped pattern. then draw a horizontal line and on one side mark it 400the other mark it 500. then place the bottom/center of the wide V at 440 and then place the bottom center of the sharp V at 465. with that illustration you can then visualize the sharp V will get the desired frequency better and stronger than the wide V, but the Wide V will have greater frequency coverage, all be it weaker, over the other parts of the spectrum. this is why better receivers are important. and this is the difference between a tuned GMRS antenna and a general purpose UHF antenna. You also have to make sure you are comparing apples to apples when testing antennas. one may do well at certain frequencies and the other may do well at other frequencies.

I cannot say that I understood your "visualization" of the situation (I work well with what I can see, but rarely do well with written descriptions...), but regarding the comment "one may do well at certain frequencies and the other may do well at other frequencies", since both radios were sitting side by side and scanning exactly the same channels (a true assortment of frequencies and bands), and both would stop on the same thing when something came through, AND the whip antenna always locked in better if both radios were not a solid lock, then I think that question is answered! BOTH antennas performed equally much/most of the time, but when they didn't, the nod went to the ABBREE 771 whip over the Nagoya... and this was NOT what I expected to happen!!!

quote:

Originally posted by Some Shot:

quote:

the one with the 15" whip would lock onto incoming signals as well, and frequently even better than the Nagoya!

Let us know what frequencies they were locking in to.

The further from GMRS frequencies, the advantage would go the the dual-band whip.

The two that I seem to have the most action on locally are: 154.920 (AL Hwy Patrol) and 463.075 (local MedFlight). Clearly one is WAY below GMRS frequencies, and the other is slightly above...

quote:

Originally posted by parabellum:
Me, watching everyone graduate from ham radio school, from high up in the gym bleachers: {takes swig out of bottle of beer, flicks ash off of cigarette}

Teacher approaches: Dude, what happened??

Me: I got left back for another year.

Teacher: Why??

Me: {shrugs} Flunked Antennas.

LOL... about the same thing I was thinking of myself, though articulated with a much greater amount of wit and humor!!!

This message has been edited. Last edited by: parabellum,

Bill, I've combined three of your posts and deleted one, which looks like a mistake. I told you about this the other day and I am telling you for the last time: Do not put four or five posts on the same page in a thread. If you want address multiple posts, combine them into one. If you don't know how to do that, then ask.

Next time, I'm not going to ask, I'm not even going to mention. I'll just delete all the spam you're putting up, and then you can spend a few days on moderated status to give you some time to think about all of this.

Do not spam these threads. If you don't know what I'm talking about, speak up.

quote:

Originally posted by parabellum:
Bill, I've combined three of your posts and deleted one, which looks like a mistake. I told you about this the other day and I am telling you for the last time: Do not put four or five posts on the same page in a thread. If you want address multiple posts, combine them into one. If you don't know how to do that, then ask.

Next time, I'm not going to ask, I'm not even going to mention. I'll just delete all the spam you're putting up, and then you can spend a few days on moderated status to give you some time to think about all of this.

Do not spam these threads. If you don't know what I'm talking about, speak up.

I just sent you a message through the forum asking how to do this as I couldn't seem to figure it out!

I have had no intention of spamming anyone, much less this thread! If that is what you think of me, I'll put myself into time-out for a few days....

Edit to add: I thought threads were a "conversation", so I was just trying to converse. Sorry I crossed some invisible line on here. My apologies!!!

Click on the Edit button of the combined message and you'll see how it's all formatted, using simple copy and paste.

Members should never have two, three, four or more posts in a row with nothing in-between from other members. This constitutes spamming a thread and all members should avoid putting up multiple posts one after the other, when they can simply combine posts with copy and paste.
Each page of thread contains twenty posts. When you put up four posts in a row, you have consumed twenty percent of a page, when it should be only five percent of a page. Threads such as this are already lengthy. Do not needlessly lengthen threads.

quote:

Originally posted by parabellum:
Click on the Edit button of the combined message and you'll see how it's all formatted, using simple copy and paste.

Members should never have two, three, four or more posts in a row with nothing in-between from other members. This constitutes spamming a thread and all members should avoid putting up multiple posts one after the other, when they can simply combine posts with copy and paste.
Each page of thread contains twenty posts. When you put up four posts in a row, you have consumed twenty percent of a page, when it should be only five percent of a page. Threads such as this are already lengthy. Do not needlessly lengthen threads.

Again, my apologies; I intended no ill! Your job is hard enough without having to deal with "problem children", and it was a line I did not realize I was crossing!!!

I will review your post to see how it was formatted... but I will say this; I was attempting to combine multiple responses into one post at the same time you combined mine. Every time I switched from one panel to another, the previous post I had copied would disappear, and all I could see was the latest one! I will study what you did and try again later when appropriate, but will not post if not successful. If that happens, I will contact you directly for any further help or suggestions. Thanks again for running a great forum here, and sorry again for making your job harder!!!

Edit to add: I just looked at the combined post, and that is EXACTLY what I was attempting to do earlier, but as stated above, the previous text would disappear when I tried to add new copied text! Not sure what happened or why, but that is what happened to me. Please feel free to contact me via e-mail to keep from dragging this on in the thread, and hopefully I can figure out what happened!

You have to copy data out of a second post you want to respond to, then click edit on the first post you made, and then paste in the stuff from the second post, and then add your comment to that part, and so on.

You have to remember, though, that if you have a compose message window open and then click edit on a second post, that first message box will be replaced. Ths is why you use the copy function of your computer to hold data on the computer's clipboard.

quote:

Originally posted by parabellum:
You have to copy data out of a second post you want to respond to, then click edit on the first post you made, and then paste in the stuff from the second post, and then add your comment to that part, and so on.

You have to remember, though, that if you have a compose message window open and then click edit on a second post, that first message box will be replaced. Ths is why you use the copy function of your computer to hold data on the computer's clipboard.

Okay, that is where I screwed up! If it's okay, I'm going over to the "SIG Forum Office" to experiment with this and see if I can get it right, AND not contribute any more unneeded crap to this thread! Thanks again!!!

Sure

quote:

Originally posted by oddball:

quote:

Originally posted by parabellum:
As this gent points out, repeater traffic would be off the scale in a disaster, and this assumes that these repeaters would even be powered in an emergency.

Most of what the YouTube guy said is mostly true but I don’t necessarily agree with all of his conclusions in all cases or for all parts of the country.

We use repeaters in my neck of the woods during storm season every year. We practice weather nets monthly. People are pretty orderly during tornado events. You don’t get on the air a jabber because the wind is blowing hard. Everyone already knows this. Reporting criteria are made clear.

Most local clubs here have backup repeaters in different locations to help mitigate power outages. They have mobile trailers and mobile towers and generators to get local comms going for these types of problems. We practice it twice each year during a nationwide “Field Day”. We have an active club that’s been in existence for 100 years and have a pretty good budget each year. Not all clubs do but most bigger cities have established clubs.

Ham radio can be frustrating due to the effects of how the sun impacts the ionosphere, which enables global communications and NVIS propagation, and it varies by day and night and time of year. It isn’t black magic, it’s just very technical and takes years to get proficient and know how and what tool to use at any given time.

I noticed the guy had a 5 Watt HF radio he kept holding up. JALLEN could work the world with that radio and Morse code but most can’t. I can’t. A $69 telescoping flag pole from Harbor Freight would do wonders for the guys end fed antenna problem. That’s what I use and I have 60 ft oak trees in my yard. And a 100watt radio, solar panels, and batteries.

As with anything, disaster communication really requires a layered solution - or set of tools. How many here have only one type of gun and one type of ammo? Similar thing.

Having a robust plan will require planning, money, study, and practice. If you just want to talk to a friend a few miles away on a HT when cell and internet are down then maybe that will work. It depends on the terrain and other factors. I recommend putting a Tram VHF / UHF antenna with a radial kit up on a 20 flagpole to help out your HT. If you want to use Winlink to email family in another state you need an appropriate radio and antenna. And keep messages short and sweet.

I could go on but my thumb is tired.

quote:

Originally posted by Jimineer:

quote:

Originally posted by oddball:

quote:

Originally posted by parabellum:
As this gent points out, repeater traffic would be off the scale in a disaster, and this assumes that these repeaters would even be powered in an emergency.

Ham radio can be frustrating due to the effects of how the sun impacts the ionosphere, which enables global communications and NVIS propagation, and it varies by day and night and time of year. It isn’t black magic, it’s just very technical and takes years to get proficient and know how and what tool to use at any given time.

I've found HF NVIS (40 and 80M) to be fairly brainless. Homemade 22g wire 1/2 wave antenna 3-5 feet off the ground lets me hit, reliably, friends from 5 to 100 miles away.

Regarding the EOTWAWKI comms on 2M and GMRS through repeaters, I made the same point back on page 22. Everybody and their brother with a radio is going to try to communicate with it. Repeaters (if they are even operating) won't handle the pile-up and neither will the GMRS bands.

Ham isn't and won't be the be all end all during a true emergency, but HF will be much better than 2M/GMRS. Once things die down a little, ham will be where it's at.

And I miss having JAllen around for his elmer expertise. Wish I'd have had the opportunity to connect with him on CW.

quote:

Originally posted by Jimineer:
<<snip>> I recommend putting a Tram VHF / UHF antenna with a radial kit up on a 20 flagpole to help out your HT. <<snip>>

Just ordered one from Amazon, along with a 50' cable to add to my quickly growing "antenna collection".

quote:

Originally posted by Gustofer:

quote:

Originally posted by Jimineer:

quote:

Originally posted by oddball:

quote:

Originally posted by parabellum:
As this gent points out, repeater traffic would be off the scale in a disaster, and this assumes that these repeaters would even be powered in an emergency.

Ham radio can be frustrating due to the effects of how the sun impacts the ionosphere, which enables global communications and NVIS propagation, and it varies by day and night and time of year. It isn’t black magic, it’s just very technical and takes years to get proficient and know how and what tool to use at any given time.

I've found HF NVIS (40 and 80M) to be fairly brainless. Homemade 22g wire 1/2 wave antenna 3-5 feet off the ground lets me hit, reliably, friends from 5 to 100 miles away.

Regarding the EOTWAWKI comms on 2M and GMRS through repeaters, I made the same point back on page 22. Everybody and their brother with a radio is going to try to communicate with it. Repeaters (if they are even operating) won't handle the pile-up and neither will the GMRS bands.

Ham isn't and won't be the be all end all during a true emergency, but HF will be much better than 2M/GMRS. Once things die down a little, ham will be where it's at.

And I miss having JAllen around for his elmer expertise. Wish I'd have had the opportunity to connect with him on CW.

NVIS is often referred to as being used for EMCOMM as you probably know. I can lower my dipole to about 10 ft or so at the center point and get an NVIS pattern for more local comms.

quote:

Originally posted by bronicabill:

quote:

Originally posted by Jimineer:
<<snip>> I recommend putting a Tram VHF / UHF antenna with a radial kit up on a 20 flagpole to help out your HT. <<snip>>

Just ordered one from Amazon, along with a 50' cable to add to my quickly growing "antenna collection".

Be sure to wrap your connectors with silicone rubber sealing tape or you’ll be buying another one in about a year. Including the one inside the Tram fiberglass pole.

I think I’m about to hit my post limit for this page but hopefully this is useful information for everyone new at this stuff.