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Messages - Quietguy

Pages: [1] 2 3 ... 12
1
General Discussion / Re: KX3 MARS Mod.
« on: October 17, 2018, 08:17:07 PM »
Hi there, Wouldn't the MARS mod render your KX3 unusable under the new FCC advisory note relating to the ability of equipment to transmit out of amateur bands?

I'm guessing you are referring to the FCC taking on Baofeng regarding violating the rules concerning commercial sales of "type accepted" equipment.  There is no prohibition against amateurs possessing or using equipment capable of out of band transmissions; the prohibition is against actually transmitting where they are not authorized.  The MARS mod does not affect amateur use of the equipment within amateur bands.  US amateurs are free to design, build, modify and operate their own equipment as long as the equipment meets FCC emission standards.  That's why kits can be sold without going through the "type acceptance" approval process.  The kit isn't a radio until it is assembled, and then it is up to the individual amateur to make sure his equipment complies.

But, some time ago I read the NTIA (the agency that regulates US Federal frequencies) had ruled that MARS members had to use equipment that complied with NTIA regulations, which did not include modified amateur equipment.  I am not a MARS member and I don't know how that played out.  The NTIA regulates Federal government frequencies, including military, and the FCC regulates civilian frequencies.

Wally

2
That's an interesting observation, but I suspect one difference is in the definition of "life expectancy" - you are looking at it from a power delivered point of view but length of service is an important criteria.  For example, I imagine most people rate their car battery in terms of how long it lasts not how many amp-hours (number of engine starts) it delivered over its life.  Also, as your calculations show, the numbers change with different depths of discharge - your example showed more power delivered at a 90% DOD versus 50%, but the reverse is true at 30% DOD: 48,000 AHr vs 36,000. 

If we use 100 AHr again, his illustration comparing two batteries at 40% DOD vs. one battery at 80% works out that two batteries at 40% DOD will provide 88,000 AHr over 1100 cycles but two consecutive  single batteries at 80% yields 36,000 AHr each, times two batteries, is 72,000 AHr over 450 cycles.  So running a single battery to 80% DOD to end of life and replacing it gives you 900 cycles and 72,000 AHr vs. 1100 cycles and 88,000 AHr.  It would take 2.44 single batteries to yield the same power output of a pair over its life.  One variable here is: how long is a cycle?  That depends on rate of discharge and rate of recharge. 

I think the take-away from his article and graph is lower DOD is a Good Thing (tm), but beyond 50% the importance diminishes as long as you don't damage the battery.  I have heard the 50% number given as a maximum-do-not-exceed number to prolong life, and the graph seems to reinforce that.  Prolonging life and delivering maximum energy may not be the same thing.

Wally

3
DMR Radio / Re: New Board: DMR Radio on Radio Preppers.
« on: August 03, 2018, 02:19:08 AM »
Is it real radio? Well, only between the repeater and your handheld, otherwise, no.

But it also makes simplex connections, so it is just as much Real Radio as any 2m/70cm HT or mobile, it just has more capabilities.  It works radio to repeater to radio for local coverage just like analog radios, no Internet needed.

Also, if you have Internet capability at home you don't have to be near a repeater for distant contacts.  You can have your own imitation repeater in the comfort of your living room by setting up a personal hot spot.  There are several, some based on the Raspberry Pi and others more plug and play.  The SharkRF Open Spot is a plug and play hotspot that allows linking to the Brandmeister network for worldwide contacts.  So you can use your HT to talk across town to a friend simplex or you can use a hot spot with Internet to talk anywhere.
https://www.sharkrf.com/products/openspot/

Cheap.  Dual band (2m/70cm) DMR plus analog FM for $170 shipped (in the US), complete with built-in GPS so two units linked simplex know how far apart they are.  Not bad for search and rescue efforts.
https://www.ebay.com/itm/AnyTone-AT-D868UV-GPS-Version-2-Dual-Band-DMR-Analog-144-430-MHz-Radio-US-seller/292319089829

Wally

4
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.

Wally

5
That looks very professional Joel, and all the buttons you need, none that you don't ;)

Gil.

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

Wally

6
It must have cleared FCC review; HRO is taking orders and says it will be available in March.

https://www.hamradio.com/detail.cfm?pid=H0-016097

Wally

7
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.
[snip]
 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.

Wally

8
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 http://www.short-wave.info/, 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.

Wally

9
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.

Wally

10
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.

Wally

11
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:

Quote
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.

[snip...]

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


www.foxnews.com/world/2017/10/30/sailors-lost-at-sea-for-5-months-never-activated-emergency-beacon.html

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

12
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.

Wally

13
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?

Wally

14
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.

Wally

15
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.

Wally

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