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Author Topic: I was right (more or less)  (Read 894 times)

KX4QP

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I was right (more or less)
« on: September 02, 2019, 05:07:59 AM »

I've had some discussions about being able to reach repeaters from my home (which is ~20 m below average terrain -- i.e. I live in a draw).  Folks had said "more power! and a better antenna!" to which I had repllied that with roundly 60 m of terrain interfering between me and the most accessible repeaters (other than the ones on a mountain pretty close to home), more power wasn't going to help -- but changing band might.

When I bought a mobile to install in my car, I bought a quad-band, 10/6/2/70 cm, 50W (40 on UHF) unit, and installed a quad-band antenna with 2.15 dB on 10 m and up to 5.5 dB on UHF.  Installation was yesterday, and last night I got the radio programmed and tested access to a few repeaters.

While I still couldn't work the 2m and 70cm repeaters that are blocked by terrain (i.e. no change from my 8W HT with upgraded antenna), I found that I was able to raise a 6m repeater with more than 30 m of intervening hilltops between me and the antenna -- one ridge quite close to home, another near the repeater.  Signal wasn't perfect -- about 37 (scratchy and somewhat weak, but good copy), but VHF and UHF repeaters near that one gave no response at all -- either I wasn't heard, or I couldn't hear the repeater.

I tried on 10m as well, but there are only two 10m repeaters within 80 km (that was the search radius I used), and I wasn't able to raise either one.  Both are further away than the 6m unit I worked last night -- nearer one is about 45 km -- which is likely a factor here.  I'm just happy to be able to reach something other than the local mountaintop machines from home, especially as the 6m repeater I worked last night cross-connects to a system of VHF and UHF repeaters in the area, giving me better coverage than I'd have from the VHF repeater 400+ m up a TV tower roundly 50 km from home, even if I could reach it, and better coverage than the mountaintop repeaters near home.

I still wasn't able to reach the UHF repeater on that same network with 300m of mountain in the way -- even with 40W output and 5.5 dB antenna gain on 70cm band -- but the 6m repeater is on the same network.  That means that once my club's repeater is back in operation and connected to that system, I'll finally be able to check in on the club's nets (at least from my car).
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KB8VUL

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RE: I was right (more or less)
« Reply #1 on: September 02, 2019, 08:18:09 PM »

A lot of people that don't have a real understanding of radio waves and how they propagate will run back to the more power statements.
Here's the thing, if you can't hear the repeater, then you can't hear the repeater, end of story.  Increasing power MAY get you into the repeater, but if you can't hear it talking back what's the point?
If you are 60 meters below the terrain in a draw, then you have but one choice, and that's increasing the height of your antenna,  a lot. 

200 foot of tower creates a ton of difficulties.
It's not a simple task, and it's certainly not cheap. 

Another option is a remote base setup with a cross band repeater that you could somehow control remotely.  BUt finding a place to put it may be difficult.

Good luck on your quest.


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SOFAR

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RE: I was right (more or less)
« Reply #2 on: September 02, 2019, 11:21:16 PM »

When I bought a mobile to install in my car, I bought a quad-band, 10/6/2/70 cm, 50W (40 on UHF) unit, and installed a quad-band antenna with 2.15 dB on 10 m and up to 5.5 dB on UHF.  

I wouldn't give much weight to dB claims.
'dB' without a qualifier, dBi or dBd, is even more questionable.

Why the focus on repeaters?

Park on 146.520 and make some simplex contacts.
« Last Edit: September 02, 2019, 11:30:21 PM by SOFAR »
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KX4QP

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RE: I was right (more or less)
« Reply #3 on: September 03, 2019, 03:53:46 AM »


Why the focus on repeaters?

Park on 146.520 and make some simplex contacts.

All the time I've been using my HT in my car during my commute (an hour each way, five days a week, for four months) I haven't heard a voice on 146.520, despite my radio set to listen there as well as whatever Repeaters I've selected.  Repeaters are where people listen and talk, so that's where I listen and call.
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SOFAR

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RE: I was right (more or less)
« Reply #4 on: September 03, 2019, 06:18:35 AM »


Why the focus on repeaters?

Park on 146.520 and make some simplex contacts.

All the time I've been using my HT in my car during my commute (an hour each way, five days a week, for four months) I haven't heard a voice on 146.520, despite my radio set to listen there as well as whatever Repeaters I've selected.  Repeaters are where people listen and talk, so that's where I listen and call.

You're not going to make any simplex contacts, using an HT inside a vehicle.
The End.
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KX4QP

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RE: I was right (more or less)
« Reply #5 on: September 03, 2019, 04:28:35 PM »

You're not going to make any simplex contacts, using an HT inside a vehicle.
The End.

Really?  I've heard folks who were quite surprised I was contacting certain repeaters at a distance of 30+ miles with an HT inside a vehicle.  I can do it at 40 miles, if I'm on a hilltop -- and that was with my HT on medium power, only 4W output (high is 8W).  This is on 2m, too -- not 70 cm that might reasonably wiggle its way out through a windshield as big as the one on a Fiesta.  By rights, I ought to get nothing in or out on 2m -- but I did and do, at what seems like reasonable distances, limited by terrain seemingly about the same as my shiny new mobile rig with six times the power and a better antenna.  I keep the radio standing upright in one of the cup holders between the front seats, and use the earpiece/mic unit that came with the radio instead of picking it up to talk.

What did change the game was being able to call on longer wavelengths -- there aren't enough 10m repeaters in this area to give a fair test, but I was able to key a 6m repeater from work, about 13 miles from the machine, all the way home, even in the low spots in the road -- and home is above 40 miles and ~60 feet below average terrain.  Even better, that repeater is 24/7 linked to a group that covers the entire Piedmont region.

Based on your suggestion, I'll go ahead and turn the dual monitoring in my new mobile rig back on and listen to the 2m calling frequency for a while -- but I don't expect to hear anything on that.  In north central North Carolina, at least, simplex seems to be pretty nearly dead on the main roads and in towns -- either that, or it magically stays outside my car when repeater signals get in and out just fine.
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K5LXP

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RE: I was right (more or less)
« Reply #6 on: September 04, 2019, 06:18:18 AM »

You're not going to make any simplex contacts, using an HT inside a vehicle.
The End.

While I may not consider it completely hopeless, it's pretty close to that.  There's numbers to go along with it.

Your HT is say, 5W.  Your rubber duck antenna is at least 6dB below unity gain, maybe 10.  So your ERP is close to a watt or so.  Your car is an attenuator, figure at least 10dB, maybe up to 20.  So now your ERP is in the milliwatt range.  When you're sitting in a car, you're what, 4 feet above ground?  Maybe 5 or 6 feet if you're in an SUV.  So using an HT in a car you're HAAT is a few feet and you're radiating milliwatts.  Yes, you can get out if the other station you're contacting has height and antenna advantage and a good repeater will usually have that.  But other simplex stations likely won't.  It's hard enough to work repeaters with an HT inside the car, but simplex is a lot harder.  Factor in that few people monitor simplex (few enough monitor repeaters) and now you've worked your way into a pretty small corner of improbability.

Here's a post I made a while back about making contacts on 6.52.  Maybe set up a beacon and run it for  a while to see if you scare anything up.

https://www.eham.net/ehamforum/smf/index.php/topic,107543.msg938659.html#msg938659

Mark K5LXP
Albuquerque, NM
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SOFAR

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RE: I was right (more or less)
« Reply #7 on: September 04, 2019, 12:14:52 PM »

The OP fails to realize the difference between a repeater antenna, that's 1,000 ft up, and a  signal from another mobile, at ground level. Not to mention, adjusting the squelch for simplex.

All this talk about dB, and wavelengths.
Yet he chooses this (High Gain *snort*) antenna.
https://www.amazon.com/WishRing-HH-9000-Quad-band-Mobile-Antenna/product-reviews/B012A6T83G/ref=cm_cr_arp_mb_hist_1?ie=UTF8&filterByStar=one_star&reviewerType=all_reviews#reviews-filter-bar

It's like he wants to fail, so he has something to complain about.

The OP is a chronic complainer, better suited for my ignore list.
The End.

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KX4QP

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RE: I was right (more or less)
« Reply #8 on: September 04, 2019, 04:54:37 PM »

The OP is a chronic complainer, better suited for my ignore list.
The End.

And, apparently, the ignore lister is a troll.

Rant in reply deleted.  Don't feed the trolls.
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KX4QP

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RE: I was right (more or less)
« Reply #9 on: September 04, 2019, 05:11:55 PM »

Your HT is say, 5W.  Your rubber duck antenna is at least 6dB below unity gain, maybe 10.  So your ERP is close to a watt or so.  Your car is an attenuator, figure at least 10dB, maybe up to 20.  So now your ERP is in the milliwatt range.  When you're sitting in a car, you're what, 4 feet above ground?  Maybe 5 or 6 feet if you're in an SUV.  So using an HT in a car you're HAAT is a few feet and you're radiating milliwatts.  Yes, you can get out if the other station you're contacting has height and antenna advantage and a good repeater will usually have that.  But other simplex stations likely won't.  It's hard enough to work repeaters with an HT inside the car, but simplex is a lot harder.  Factor in that few people monitor simplex (few enough monitor repeaters) and now you've worked your way into a pretty small corner of improbability.

A couple minor corrections -- my HT is 8W, not 5, and I upgraded from the original rubber duck, so I'm pretty sure I'm little if any below unity gain.  However, the car certainly attenuates, and a Fiesta puts my antenna more like two feet above ground than even four.  Still, I see why there's a strong disadvantage trying to make simplex contacts (though I'm very unclear why someone I'm now ignoring considers it the only way to fly).  However: even with my new mobile and better antenna (mine seems far better than the ones that garnered all the negative reviews -- one of those was mainly aimed a the mount, which is sold separately!), I don't hear much activity on *any* part of 2m, nor on 70 cm, nor on the few 6m and 10m FM repeaters in this area.

Today, I called CQ on 146.520 (at high power, 50 W, albeit from around 3 feet antenna base height and antenna barely over unity gain, but at least outside the rolling attenuator) every 2-3 minutes for most of the hour commute -- and still haven't heard a voice on that frequency.  This radio ought to have a range of at least ten miles in simplex.  But you can't talk to anyone if no one is on the frequency.

The last twenty minutes of my trip home today I put the radio in scan (scanning all the repeater frequencies I have programmed, from 10 m to 70 cm) -- and promptly found a local net on a 2m repeater that I wouldn't have been able to hear from that location with my HT.  It was closing out by that time (starts before I leave work) -- but that's additional evidence that this radio and antenna are working pretty well.
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KB8VUL

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RE: I was right (more or less)
« Reply #10 on: September 04, 2019, 07:57:55 PM »

I do love the guys that tell you how you should be doing this or you should be doing that. 
Do whatever makes you happy and don't worry about what others are doing.

As far as manufactures gain figures, yes they are typically inflated.   Sometimes by a lot.
But it's not the gain figures as much as it is a 5/8 wave antenna of reasonable design will out perform a 1/4 wave antenna, consistently.

Sure I have seen antenna gain numbers on vertical antennas claim levels reserved for parabolic microwave dishes, but it still works better than a 1/4 whip, or a rubber ducky attached to the radio.
And the statement of try talking simplex on 52 instead of the repeaters.  Did you not bother to READ the original post?  And the terrain issues he faces?  Sure that will work if someone happens to be down in the draw with him.... But if he's the only one in that area, he's done...

Now I will say that if you are willing to run HF, then you have other options.  First off HF on the lower bands will provide you with some ground wave propagation.  That will help being in a hole.
The other thing to look into is NVIS antenna systems.  You will be limited to 40 and 80 meters with them typically, but they do work. 

HF mobile is also an option if you have a car your wife doesn't also drive. Mobile HF antenna's are an eye sore to many, but they can be effective.
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K5LXP

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RE: I was right (more or less)
« Reply #11 on: September 05, 2019, 04:19:19 AM »

my HT is 8W, not 5,

It may be called 8 watts, but I would bet you it doesn't have an 8 watt carrier output.  Practically speaking the difference between 8 watts and 5 watts is about 2dB, and in an FM system this makes a barely perceptible difference.  Splitting hairs I know, but just something to know going forward.

Quote
I upgraded from the original rubber duck,

Hard to say, because actual ERP depends on the radio it's attached to and the effects of objects in proximity to it, not the least of which is your head.  If you ever watch the SWR response of a rubber duck on a handheld antenna analyzer you see pretty quickly it's anything but static.  Apples to apples it can help but I doubt it's by more than a few dB.

The elephant in the room is shielding by the car and your height above ground.  Line of sight for an antenna 5 feet off the ground is about 2 miles.  That assumes flat terrain so as you peak on hilltops you get more, in the valleys you get less.  So consider on simplex other stations around you need to be pretty close or have elevation on you.  Throw in sparse population and you have a formula for few contacts.  Focusing on repeaters and linking is the right way to go for now, though leaving a radio on 52 might be fun just due to the uniqueness of making those rare contacts.  When I travel I always put the other receiver on 52 while I scan repeaters on the other.  Another thing to throw out there is when traveling the hinterlands, V/U activity is sparse at best and that's what prompted me to try HF mobile.  Fast forward a few decades later and HF mobile is still one of the most favorite things I do in the hobby.  There is always someone on somewhere, and it's a hoot to work someone across country or across continents just rolling down the road.   You'll figure it out, now that you have a decent enough mobile you can work up to something at the house, and find the niche of whatever it is you like to do with ham radio.

Mark K5LXP
Albuquerque, NM
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KX4QP

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RE: I was right (more or less)
« Reply #12 on: September 07, 2019, 01:53:18 PM »

I don't normally talk on the HT with the antenna by my head -- when it's in the car, I use the headset and stand the radio in the center console cup holder.  As you note, however, that does nothing for the height and attenuation issues.  Everything I've seen says the Nagoya 771 I have on there (yes, a real one, not a counterfeit -- I checked) is a huge improvement over the stock rubber duck -- but again, it's still inside the car, and more like two feet above ground than five.

Regardless, I did in fact manage a brief 2m simplex QSO (with my installed mobile, not the HT) on the way home from work on Thursday, my first ever -- after calling a long CQ every couple minutes for above twenty minutes, someone answered back, and by the time he could say my signal was a little scratchy and I responded after turning my power to maximum, I'd gone out of range or been terrain blocked, and we lost each other.  The next afternoon, I picked up a local net on 2m, from a repeater that was about 25 miles away at the start and closer to 35 by the time they closed, and never lost signal even down in the low spots.  I'm still of the opinion that even with power and better antenna, simplex isn't much use from a moving vehicle in hilly areas.  It would almost certainly improve on longer wavelengths, I'd think; 6m and 10m diffract over hilltops a lot better than 2m or 70cm.

I don't see myself trying to put even a 20m capable antenna on my Fiesta -- the quad-band (10m to 70cm) whip with coils I have on there now looks like a CB antenna from the 1970s (though the "better" antennas then, on 11m, were a good bit longer than this one).  People must use loading coils and capacitance hats to get antennas on cars that work with 20m or longer.  There is NO WAY a 38 foot 5/8 wave whip is going to stay on when I go under an overpass at 55-65 mph.
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K0UA

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RE: I was right (more or less)
« Reply #13 on: October 11, 2019, 12:22:59 PM »

Quote
V/U activity is sparse at best and that's what prompted me to try HF mobile.  Fast forward a few decades later and HF mobile is still one of the most favorite things I do in the hobby.


Same here. I make far far more HF contacts mobile than V/U.  I am fully equipped for V/U also and do use it to hit local repeaters, but my "bread and butter" is HF mobile.  More 20 meters than anything, although I have made contacts from 80 thru 6 meters mobile.  There is always someone to talk to on HF mobile. I have worked several countries in the caribbean, south america, africa and europe and on Asia on 20 meters. Let alone many many north american contacts. 

Heck I worked a dozen guys in California on the way home from eating dinner in Nixa Mo. to my home in Branson, Mo.  About a 30 minute drive and yes the California QSO party was going on so there were lots of "targets", but still, HF mobile is the way to go.  I have a Little Tarheel II on my Silverado.  It ain't too big. I did replace the stock 32 inch whip with a 48 inch one to improve performance a bit. so it is 54 inches tall.  or a bit taller on when tuned to 80 meters. But still under 5 foot. It works very well.  Now believe this or not, up to you, but my first HF mobile antenna was an MFJ 3 foot tall "mini-hamstick". Yep, a dummy load on a stick, but I made a lot of contacts on 20 meters on that thing. Including some caribbean contacts. So don't give up on the HF mobile idea until you have tried it.  I run a little FT891 in the truck.  It is about the size of a V/U rig and puts out 100 watts maximum.

So is the Tarheel screwdriver antenna a bunch better than the 3 ft. tall mini hamstick?  Yep. It is. But I did have fun with the $18 hamstick.

Of course the Tarheel screwdriver antenna was $400 and the controller another $139 so there is that..  I stand by to help answer any questions about my HF mobile installation or anything else you want to talk about.

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73  James K0UA

K0UA

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RE: I was right (more or less)
« Reply #14 on: October 11, 2019, 12:54:24 PM »

Here is the interior of the truck showing the little Yaesu Ft90r Vhf/Uhf rig mounted to the dask It is tiny. and FT891 mounted to the floor. At this point back in January 2019 I am still using the manual controller for the Tarheel antenna.



« Last Edit: October 11, 2019, 12:57:13 PM by K0UA »
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73  James K0UA
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