The Ham Radio Thread

DAA

Well-Known Member
If there is one you and whoever you want to talk to can both see, or at least see the peak it's on, that's a good bet since you both have line of sight on it. Else, around here, you've got the intertie which chances are you both can hit a repeater on it.

Intermountain Intertie

I've never used it. Just monitored traffic a few times.

Have only ever attempted and made just one, single "not trail buddy" contact though so I'm the furthest thing from experienced. The one contact I did make, was on a similar but smaller system in Nevada. It was pretty cool though, as I was using a Baofeng HT and from a high point, was able to key up a repeater over 30 miles away (with a Baefeng!) and then talk to a guy who was another 100 miles further from it (he was actually in Idaho). He was hitting a repeater much closer to himself. The linked system allowed our two separate repeaters to talk to each other. He was loud and clear for me. He said I was very snowy on his end, but he could hear and understand me just fine though the snow. I just wanted to see if that would be possible with my little handheld and was sort of surprised when someone actually answered me :D.

- DAA
 

TurboMinivan

Still plays with cars
Location
Lehi, UT
How do you decide what repeater to use to talk to someone sort of far away? Do you just give it a try? Look at a map and find one that is in the middle?

More or less. When choosing a repeater, I do like to focus on ones labeled 'wide area coverage' by the VHF Society. Remember that web page I showed you? Look for the X in the Info column. Don't ignore terrain when you do this--it can certainly be a factor, especially around here.

More importantly, you must take into account the radio hardware you and your friend are using. For example: if he only has an HT but you have a mobile radio, I would select a repeater much closer to him than you because your radio can 'reach out' much further than his. So let's say you want to talk to Kevin B up in Magna, and he's on a handheld Baofeng but you have the mobile radio in your Jeep. I would choose a repeater on Farnsworth Peak. Depending exactly where in Magna he is, his radio signal will only need to travel 6 or 8 miles to get to the repeater. Your house is 30 miles from that peak, but your mobile radio and its Larsen antenna can easily handle that distance.

By all means, feel free to experiment. That's what the hobby is all about. :)
 

mesha

By endurance we conquer
Location
A.F.
They both checked in. After check in the question of the day was what did you do this week and what’s your favorite pizza topping :)

The little girl that was net control said it was her biggest check in ever. Probably 15-20 people. There was a few minutes at the end so they opened it up and Cedar got brave and asked the group their favorite animals. Lol
 

frieed

Jeepless in Draper
Supporting Member
Location
Draper, UT
I took the plunge for a mobile radio today. After the weekend Swell run where we spread out so far to avoid dust and lost contact with the HT's I'm ready for more power. I'm only concerned about trail chatter so I went with a single-band(2m) Yaesu 2980R.
80W of 2m goodness for $140.
 

TurboMinivan

Still plays with cars
Location
Lehi, UT
Eric: I'm sorry I didn't see your message to me until after you posted the above. However, I will say you made a good choice. A good 2m radio (like the Yaesu you chose) will go a long way toward keeping you in touch with your trail mates. True, you won't have the 70cm band available to you... but all your buddies have 2m on their mobile radios, so you should be completely fine.

Just be sure to pair it with an excellent antenna! Choose a half-wave design. I would still suggest you opt for a dual band antenna (the Larsen NMO2/70B) simply because if you upgrade to a dual band radio in the future you'll already have the antenna for it. The cost difference compared to the 2m-only equivalent will be small, so why not?
 

DAA

Well-Known Member
Could use some help with APRS.

New Yaesu FTM-400XDR, built in GPS and APRS function. Believe I have all the settings for APRS turned on, APRS modem ON, GPS ON. I see the beacon icon in my display, the GPS lock icon and "APRS" in the display.

B band tuned to 144.39. Transmit on high.

Path at factory default, WIDE1-1, WIDE2-1.

BAUD 1200.

Temporarily set interval to 1 minute while I'm troubleshooting.

Receiving lots of APRS beacons.

Am not getting my own beacons back and am not showing up on aprs.fi.

So... One suspicion, is that my install is not transmitting very strong (no ground plane to speak of) and my beacon packets simply aren't reaching a digipeater. I just took a drive, went up to the B where there is good line of sight on lots of peaks, tried keying up the 147.12 Farnsworth Intertie for a radio check and immediately got a reply that I was "loud and clear". But still not getting my own APRS beacons back.

Could still be my TX strength, but, I'm thinking if I can hit Farnsworth loud and clear, I ought to be hitting a digipeater too? I'm not sure exactly where a good APRS digipeater is around here, else I'd drive right under it and do some manual beacons.

So... Any ideas?

Know where a digipeater is located I can get close to in order to see if it's just TX strength?

Something in my settings I should look at?

Thinking I might score a mag mount antenna for a test control. Could always use it to move my radio to my truck so not wasted $. Separate question I guess, but suggestions recommends for a mag mount antenna? Or, better off with a mag mount NMO instead to screw my Larsen 2/70 onto?

Thanks in advance!

- DAA
 

DAA

Well-Known Member
So, it is my TX strength. Which is because of either my antenna install or the antenna itself.

Ran out to Eric's house to borrow his SWR meter and his mag mount antenna. Knew before I got there that my problem was TX simply because he couldn't hear me on simplex until I was almost on top of him.

SWR was sky high. Put his mag mount in the middle of my hood and started the APRS beacon and started seeing my own beacons coming back in a few minutes. Can see them on aprs.fi now too.

So, THAT is solved. Sorta... Now I have to trouble shoot the antenna.

First suspect is grounding of the mount and with Eric's mutli meter we confirmed that it's not grounded as well as I thought it was. Definitely need to improve the ground there.

Not completely sure my antenna isn't a problem too though? Because...

untitled-1W_1.jpg


Larsen 2/70 NMO

There is continuity between that outer threaded ring and the antenna mast? But NOT between that center tab and the antenna? Shouldn't that be the other way around? The center tab has continuity with nothing that we could find. Not the mast or the outer ring.

We confirmed that my cable and the continuity from PL-259 to NMO mount seem good.
- Continuity from center of PL-259 to center of mount
- Continuity from shield of PL-259 to outer ring of mount
- No continuity from center of PL-259 to shield
- No continuity from center of mount to outer ring

Which... If I'm adding this up right, since there is continuity in the antenna itself from outer ring to antenna mast, means the shield of the PL-259 and the outer ring of the mount, not the center, is driving the antenna? Again, I don't know, I'm asking the question, but shouldn't the center pin be driving it?

Bad antenna? Or did I screw something up? Or is that actually how it is supposed to be?

I'll get to work improving the grounding on the mount, either way - it definitely needs improvement. But I'm not ready to rule out a defective antenna?

Thanks!

- DAA
 

DAA

Well-Known Member
More diagnostic, partly putting it out here so I don't have to remember it, partly in hopes it will help someone help me, or somebody else in the future.

- Removed PL-259 from back of radio and checked continuity from outer barrel (shield) to body using a door striker and it's near perfect at 0.2 ohms
- Checking continuity from outer ring of mount directly to battery, not so good at ~40 ohms

So, I have good ground to the body, but not to the battery. Does the body ground being so good mean my mount is grounded good? Or is the battery resistance what matters? I googled it, seems like if I'm getting no resistance from the coax outer shield to the body, I should be good to go.

Gonna look at improving the ground to the battery anyway.

That antenna continuity has me bugged though. Have been googling and haven't found any description of how to test one with a multi meter.

- DAA
 

TurboMinivan

Still plays with cars
Location
Lehi, UT
Put his mag mount in the middle of my hood and started the APRS beacon and started seeing my own beacons coming back in a few minutes. Can see them on aprs.fi now too.

So, THAT is solved. Sorta... Now I have to trouble shoot the antenna.

Great test.

Not completely sure my antenna isn't a problem too though? Because...

untitled-1W_1.jpg


There is continuity between that outer threaded ring and the antenna mast? But NOT between that center tab and the antenna? Shouldn't that be the other way around?

Upon reading you post, I set my laptop down and went outside. I took the Larsen NMO2/70 off my Suburban, then brought it into the garage to test with my multimeter. I discovered the exact same thing that you did: the steel whip shows continuity to the bronze ring, but not to the tab. This must be one of those instances where things are different than they appear, because my radio functions perfectly. This must not be your problem.

However, I could not help but notice the center tab of your antenna in your photo. I see a scratch or two across the tab's surface. What I do not see is any evidence of it making contact with your NMO mount. When I took my antenna off the Suburban, my center tab has a sharply-defined shiny circle in the middle of it--this is evidence of it making solid contact with my mount.

I suggest you gently pry the tab out a bit (ie, away from the whip antenna) with your finger, then reattach it to your mount and give it another try.
 

frieed

Jeepless in Draper
Supporting Member
Location
Draper, UT
Dempsy,

Is there a spec for how high the center section of the mount is supposed to be above the outer ring, or is it just "high enough to hit the center tab on the antenna"
 

TurboMinivan

Still plays with cars
Location
Lehi, UT
Is there a spec for how high the center section of the mount is supposed to be above the outer ring, or is it just "high enough to hit the center tab on the antenna"

That's pretty much it. In the past, I've heard of people who have installed antennas (not only this Larsen but also others) which use a bent tab in the center like this one. They've sometimes had issues with poor contact, and the fix is always the same--bend the tab a bit and reinstall. When I installed both of my Larsens, I bent the tab out a bit just to ensure solid contact. Seems to have worked well for me.

I suppose you could measure the height of the center tab of your mount, then measure into the cavity of your antenna, and make sure you'd have contact....
 

frieed

Jeepless in Draper
Supporting Member
Location
Draper, UT
For my install, I went with a cheaper dual-band 5/8 (mfj-1729) but might change to a better one and mount it on a bed stake pocket.
With my mag mount I have it tuned to SWR 1.7/1.5/1.7 @ 144/146/148Mhz when power is 5W or 10W. At 30W or 80W it drops to 1.1 across the full band.
 

I Lean

Mbryson's hairdresser
Vendor
Location
Utah
When I first installed my HAM, I had a similar issue with the antenna not contacting in the center...in my case, it was because the NMO mount came with a rubber gasket type thing for the base of the antenna to smash against, and the antenna had its own O-ring built in. I just had to remove the gasket and everything was great.
 

DAA

Well-Known Member
So... I'm receiving my own beacons back now and showing up on aprs.fi, with my own antenna.

I am not positive exactly what made the difference.

Suspected that tab too. Bent it out as suggested every time I had it off, which is three, four times total now. Every time I take it back off, it looks like the picture. I bent it out "good and proper" this last time. Like had it sticking out past 45 degrees.

I have the center pin of the mount sitting as proud as it will go. The outer ring of the mount bottoms on a shoulder. If that shoulder isn't flush with the top of the mounting surface, the center pin doesn't sit as high as possible and the outer ring doesn't tighten down as far as possible either. I made sure the shoulder was just shy of flush and that the center pin is sitting as tall as possible. Edit to add - I'm using a Larsen NMO "thick" mount, as my mounting surface is about .430" thick. So that part, about the shoulder and all, might not make sense unless you've messed with one of these thick mounts.

And, lastly, I mentioned that I had nearly perfect ground from shield and mount to the body. But 40 ohms from mount to battery. Upon further investigation, I had 40 ohms from the body to the battery - period. From anywhere on the firewall. Not just the mount. LHM goodness? So... I ground strapped from the firewall to the intake manifold and got body to battery, as well as mount to battery, down to near zero. That sucker is GROUNDED. Maybe my tail lights will be brighter now too? :D

I'm going to call it a battle victory. Not sure about the war yet. Have my own SWR meter on the way, be here this week. Won't rest until I see good SWR out of it. But, it is hitting APRS digipeaters now. Which it wasn't this morning. Wife is happy she'll be able to just look on her phone and tell the authorities where to start searching for the body :D. I'm happy I got it working.

Had fun doing all this.

- DAA
 
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