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Messages - Quietguy

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General Discussion / Re: Have you tried the 160m band?
« on: July 04, 2018, 07:24:10 PM »
As I said before, I have no operating experience on 160m...  but I think maybe some options are being overlooked in this thread.  IMHO DX contacts with random hams is not the goal in prepper radio; reliable local/regional comms via NVIS (what RadioRay refers to as "one tank of gas range") is more relevant.  Any horizontal 160m antenna a normal non-contesting ham puts up is going to be primarily NVIS by definition - if we consider NVIS as any horizontal antenna less than 1/8 wavelength above ground (one common definition) then anything below 65 feet is NVIS.

I mentioned earlier in the thread the case where a friend located about 120 miles from me wanted to try 160m on Pactor 3 during the daytime.  He was using his random length doublet mounted about 4-6 feet off the ground on his back yard fence.  It worked well getting to me on 80m so he wanted to try 160.  I could not tune 160 with my main antenna so I was going to try an alternate antenna to see if it would tune and was in the process of switching cables to the remote tuner when he keyed his transmitter.  My Icom IC-706MkIIg, which had only about 20 feet of coax laying on the concrete floor connected to the antenna port, immediately keyed up in response.  I was startled at how strong his signal sounded on my radio and I had to quickly kill the power because there was no antenna load for the radio.  We were coordinating on the telephone at the time and he had inadvertently keyed his rig.  I could not tune the alternate antenna either, so the test was limited to how well I could hear his signal.  Based on the response from the coax, I believe I could have made a Pactor 3 contact with him using a quickly deployed short doublet laying on the ground, or maybe strung a few feet above ground, that was a length chosen to be "tunable" on 160m.

Think about it - a couple of nights ago I sat in my house playing with a tiny little Sony Walkman AM/FM portable radio with a loopstick antenna about 2 inches (5 cm) long, powered by a single AA battery.  I was able to tune in a strong signal from a Vancouver BC AM station 200 miles away.  The station is on 1130 KHz (265 meters) and the signal was solid.  A few nights earlier I had tuned in an AM station in Reno Nevada, 500 miles away, on 780 KHz (385 m) again with a good solid signal.  Ok, both of those are Clear Channel 50 KW stations with tall towers, but 50 KW is only 5 S units better than 50 watts, and I was using a 2-inch receiving antenna.

As the bottom falls out of the solar cycle the upper bands will get very hit and miss.  It has been said that 20 meters is going away as a reliable band; 40 meters will take the place of 20 and 80 meters will take the place of 40.  That means you almost have to go to 160m if you want to replace 80m as the reliable NVIS workhorse.  Your 160m antenna does not have to be an optimum 1/2 wavelength dipole to work, you just need to be able to couple it so your radio sees an acceptable SWR.

As for "nobody there" - well, what is your goal?  If you are doing "prepper" comms you should have an established network of contacts that you are practicing this stuff with.  I'm not talking about a camping trip "help, I've fallen and can't get up" general call for help, I'm talking about staying in contact with people who are important to you.


That looks very professional Joel, and all the buttons you need, none that you don't ;)


Is there a photo in Joel's post?  If so, it's not visible...


It must have cleared FCC review; HRO is taking orders and says it will be available in March.


Morse Code / Re: cw on 2 meters
« on: January 06, 2018, 11:13:49 PM »
I have been having good luck doing 2 meter digital and CW through my comet vertical, to my friend about 25 miles away over rough terrain using a J-pole 25' up, here in Idaho.
 Maybe we are just lucky?
No, you are both using vertical antennas so you don't see the mismatch.  The problem comes about when the antennas at each end are different - when one is horizontal and one is vertical.  That problem isn't present when both antennas have the same orientation. 

Historically, horizontally polarized antennas were preferred over vertical because they are quieter - most noise tends to be vertically polarized.  That's why weak signal operators tend to use horizontal polarization.  But when repeaters became common and vertical antennas were installed on vehicles, vertical became the polarization of choice for VHF/UHF FM.  Vertical antennas are much more convenient than horizontal to mount on a vehicle.  But that choice didn't carry over to weak signal work, so while you and your buddy are fine talking to each other you both will see significant losses if you try to contact weak signal stations with the more traditional horizontal polarization.


General Discussion / Re: 3.818MHz Net on Sunday nights
« on: November 14, 2017, 06:39:18 PM »
BTW - is there a place to look up SW transmission information? That is a list of transmitters on the air.

Several, one is, which shows HLL Seoul Meteorological Radio (Korean, Japanese, English, Chinese) on 5858 kHz or R.FARDA in Persian on 5860 kHz.

There are also smart phone apps with schedules.


Tactical Corner / Re: Loss of Water
« on: November 07, 2017, 06:36:21 PM »
Nice!  I worry about it handling the pressure of house water, but something like that has a lot of potential.  We don't plan on being in this house more than 5 more years, so this idea is for the next house.

One option is to not connect it in-line with the house supply, but put a 12 volt RV pump on the discharge outlet and back-feed it into the house system as needed.  Close the main supply valve from city water so you aren't trying to feed water to the whole neighborhood.  You can use a garden hose to make a temporary connection from the RV pump to a convenient hose bibb, with appropriate freeze protection as needed.  That should be good enough for sanitation purposes.

A non-permanent installation like that could be done in a day and the whole thing moved with you to your next location.  Or, leave it behind as a rain-water collection system for the garden.


General Discussion / Re: Have you tried the 160m band?
« on: November 03, 2017, 09:35:50 PM »
What do you think? Try it? Don't bother?

I haven't had an antenna up yet I could tune on 160, but I had a single eye-opening experience with it.   A few years ago I was running NVIS Pactor tests on 80m with some friends, and one wanted to try his NVIS antenna on 160.  He was about 100-ish miles north of me and running maybe 50 watts or less.  I knew I couldn't tune to connect but we decided to see if I could hear his call.  I was switching antennas and had the incoming antenna coax disconnected from the LDG antenna coupler, which was connected to the radio with about 15 or 20 feet of coax.  I was on the telephone with my friend when he hit the connect button early, and damned if his signal didn't couple to my IC-706MkIIG through that 20 feet of coax and my radio tried to answer.  Of course the SWR was through the roof so I hit the power switch to shut down the radio but I was in disbelief over that - his NVIS antenna was one of those run-along-the-fence-top affairs about 5 or 6 feet off the ground.  I don't know how long it was, but it put a strong signal into my radio through maybe 20 feet of coax as an antenna.

Ever since then a 160m antenna has been on my list of things to do since I have the space.  But, physical problems have kept me from doing any antenna work for some time now, so it is still just "on the list".

Yes - try it.  Otherwise you will never know.


General Discussion / Re: Lost at sea 5 months without comms
« on: October 31, 2017, 08:11:19 PM »
The plot thickens, as RadioRay would say.  At least I think RadioRay would say that.  Now they admit having an EPIRB, but never activated it:

During the post-incident debriefing by the Coast Guard, Jennifer Appel, who was on the sailboat with Tasha Fuiava, was asked if she had the emergency beacon on board. Appel replied she did, and that it was properly registered.

“We asked why during this course of time did they not activate the EPIRB. She had stated they never felt like they were truly in distress, like in a 24-hour period they were going to die,” said Coast Guard spokeswoman Petty Officer 2nd Class Tara Molle, who was on the call to the AP with Carr.


Experts say some of the details of the women’s story do not add up.

I'm no sailor, but something smells fishy to me.

General Discussion / Re: 3.818MHz Net on Sunday nights
« on: October 10, 2017, 12:21:14 AM »
They're sure proud of that unit! Did I really see them for $1500? I'm looking at the County Comm setup.

They have been discontinued but there is currently one on ebay for $200 Buy-It-Now.  I have had one for years and I like it, but I can't imagine anyone paying $1500 for one.  The CountyComm GP5-SSB is a nice little receiver, but the TH-F6A is a tri-band (2m/1.25m/70cm) handheld transceiver with wideband receive coverage - a completely different thing.


Net Activity / Re: Global Radio Relay Network
« on: August 28, 2017, 07:58:44 PM »
This is the main issue in traffic handling groups, all of them, getting people on the air at the right time, regularly.

Peer to peer digital works extremely well.  Given power availability - doable with solar - allows 24/7/365 monitoring and message capture.  I have done it over extended periods with Pactor before the newer soundcard modes were available, and I am told the new Winlink Express (new name for RMS Express) supports peer-to-peer on HF using sound card modes.

Asynchronous communications completely removes the need for simultaneous operating, but it isn't popular because it isn't "fun".  If the station is well configured with reliable equipment the operator is downgraded to a button-pusher.  Not much fun, but boy does it ever work efficiently.  Yes, it requires a computer, but if you have one why not use it?


Batteries & Solar / Re: Man Portable Off-Grid Power for Amateur Radio
« on: June 27, 2017, 05:20:49 PM »
I almost forgot the proof-of-concept. Here's my field station from last weekend

Is there a photo attached to this post?  If so, it hasn't been approved and we can't see it.


General Discussion / Re: Backpacks
« on: June 12, 2017, 01:11:01 AM »
(My emphasis.) There is a large empty space after this sentence and before the two concluding ones, but I see absolutely no link(s) nor pictures or any other kind of illustration in between.

I suspect Jon's photos are waiting for Admin approval before we can see them.


Antennas / Re: More info on the modified off center fed dipole
« on: April 28, 2017, 04:51:54 PM »
Very interesting, thank you!


Gil, we can not see images in posts until you approve them.  Right now I can't see any images in this thread or Lamewolf's original thread.  Apparently that was a change you made when you implemented the paid subscription plan, images posted by non-subscribers have to be moderated (approved).


Antennas / Re: Super Gain 9db 40m NVIS Antenna.
« on: March 24, 2017, 06:33:40 PM »
Thanks Wally, very informative! What's the book?

It's "Electronic and Radio Engineering", 4th ed, by Frederick E. Terman from 1955.  It was a college textbook still in use back in the mid-1960s.  It was used in some of my courses, which is why I happen to have a copy.  Sigh, yes, I'm that old and obsolete...

I can see that in my minds eye, but the gain they are speaking of in this article is going straight up !  Good for NVIS, bad for DX !

That was pretty much the author's point - reduce interference arriving at a low angle from foreign shortwave broadcasters on 40m and favor high-angle NVIS regional contacts.  I don't believe the term NVIS was used back in the '60s when this article was written, but they certainly were aware of the effect.  As DJ6KR mentioned in his post, the significance of this article is the reflector laying on the ground underneath the antenna wire directing more of the energy upward.  Terman's book (Figure 23-36) shows "Directive Gain" of about 8 at  a spacing of 0+ to about 0.1 wavelength and then steadily dropping to about 4 at 0.3 wavelength, where the plot ends.

The same figure has "Radiation Resistance" plotted at the same spacing scale, and it gets better as spacing goes up.  The downward sloping Directive Gain plot crosses the upward sloping Radiation Resistance line at a spacing of about 0.17 wavelength.  This yields a Directive Gain of about 7 and Radiation Resistance about 50 ohms.  That is probably the sweet spot for overall efficiency, but it puts the antenna up about 22 feet, which is still NVIS territory, but is much less convenient than 7 feet.  Additionally, Terman's figure is based on a reflecting screen beneath the antenna; 3 wires 6 feet on center may be a good approximation of a (40m) screen at 7 feet height but I wonder if additional reflecting wires would be necessary with higher antenna elevations, just because of the geometry.  At 7 feet the "screen" is wider than the antenna height, so would a 22 foot high antenna require a much wider "screen"?  I suspect it would to get the maximum effect.


Antennas / Re: Super Gain 9db 40m NVIS Antenna.
« on: March 23, 2017, 09:11:28 PM »
It is all about the reflector on the ground under the Antenna, I think.

Yes, I have a copy of Terman's book that is referenced in the article.  Terman discusses a "Half-wave Antenna with Reflector" starting on page 903 and derives the gain.  He shows plots of gain compared to radiation resistance as a function of antenna to reflector spacing.  Radiation resistance (and efficiency) goes way down with small spacing, while gain stays around 8 up to a spacing of about 0.1 wavelength (about 13 feet on 40 m) before falling off with increased spacing.  He says:

"In order to prevent incidental loss resistances from making the antenna efficiency very low, the spacing S should accordingly be at least 0.05 wavelength, and preferably 0.1 wavelength."

The article uses 7 feet, which is about 0.05 wavelength at 40 meters, but Terman's chart shows you would have better efficiency without losing gain if you made the antenna 14 feet high.


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