You guys want a good portable antenna, try the Eagle One Vertical at www.w8afx.com Its basically a 40 meter quarter wave vertical (33 feet tall) and works great on that band without a tuner but will work other bands with a tuner.  I have one up at home with an Icom AH4 tuner at the feedpoint and it works 10 thru 80 meters via the tuner.  The good thing about the Eagle One is that it is telescopic and collapses down to 44 inchs when not in use !  The guy that makes them, Steve Sheers is a super nice guy to deal with and sells them by itself, with a tripod mount, or a ladder mount kit for RV's and motor homes.  I think he also sells a mount that goes on a trailer hitch for stationary mobile operation.  Check them ot.

Quote from: gil on August 17, 2013, 02:39:16 PM
National Geographic is at it again. They did a good job making preppers look like fools in "Doomsday Preppers." Some were of course, but others had good plans. Now they have a family building a medieval style castle! I am not quite sure what to think... National Geographic used to be a reputable, even prestigious organization. Now it's a dog-and-pony show producer. Maybe it will get more people thinking about planning, but the way they present the subject has not been flattering or serious. It isn't a documentary, it's entertainment. Oh well, at least the patriarch has two great-looking daughters ::) The format is very much like "Doomsday Preppers." They probably found them casting for that show and decided that they were original enough for their own. Have you guys seen the previews? Are you going to watch it? What do you think?

Gil.

Anything on TV is designed to do 2 things, one is to entertain, and the second reason is to help sell advertising.  Always take "EVERYTHING" you see on TV with a grain of salt !  Even the so called survival shows, as I've seen one of the "survival gurus" do things that could get you killed if you follow his advice !  For example: "I can't positively identify this mushroom as non poisonous, but I'm so hungry I'm going to eat it anyway"  How stupid !  And then squeezing water out of animal dung and drinking it, can you spell parasites ?

I'll take that band that runs from 1.8 to 30 mhz !  ;D

Quote from: RadioRay on September 22, 2013, 08:26:05 PM
Reminder: every Sunday there is a net held in SSB (apparently voice can be sent over radio - who knew?) Right now the freq is 'around' 7242LSB, depending upon interference.  It will move UP the band to find a clear spot.  Net control is Ruth, whose voice is easy to find on a band filled with grumpy old men.   >:( >:( >:( >:( >:( >:(  :-*  >:( >:( >:( >:( >:( >:(


'SEE' you on the radio.  This is the one time per week I am in voice on the radio.


de RadioRay ..._ ._

I monitored 7.073 and 7.242 for about 3 hours starting about 7pm yesterday (Sunday) and never heard the net on PSK or on SSB, have they quit running the net ?  I listened also on 3.818 with no luck, so what gives ?

Quote from: cockpitbob on November 05, 2012, 10:25:25 PM
Too much fuel and specialized parts for me.  If this were 25 years ago I'd be saying I wanted an air cooled beetle.  10 years ago I would say I wanted a Toyota pickup.  But today I'm not sure.  When the SHTF dust settles and there's nothing left but cockroaches, AKs and zombies, what's the vehicle that will still be running?

A bycycle !

I heard a local ham here say that amateur radio was the original internet !  ANd when I asked him what he meant' he said that the govt allowed us to get licensed so that the were radio stations setup everywhere that they could take over when needed and now the internet has take the place of amateur radio and they will now communicate over our computers instead of radio.

Quote from: s2man on May 12, 2013, 02:15:39 AM
Well, I see a flashlight.  I saw an ad this week for flashlights. It said, "Be prepared when the lights go out".  So, I guess you are all set ;-)

LOL.  I almost did a spit take when I saw the pistol.  This is the radio preppers forum, after all.  Mine is in the cabinet, nearby.  So you are more prepared than I am. 

Seriously, the grounding is impressive.  The ground rod for my house a/c power is right outside of my office.  But I don't think I want to tie my electronics to that...  And the open wire is interesting.  I haven't bumped into that, yet  (And I've read 0.02% of the literature available).  It reminds me of the wiring in a Victorian house I owned.

Nothing wrong with using the AC service ground as "ALL" grounds are required by most electrical codes to be bonded together anyway and they should be !

Quote from: WA4STO on April 15, 2013, 03:53:29 PM
Hi guys.  Thought I'd put up a snap of my station as of April of 2013.



Most of the stuff is fairly 'standard' to most of you but the antenna feed lines and the method of grounding might be of interest, mostly because most amateurs these days would rather use coax cable rather than the open wire feeders shown above.  Coax is ok for one very narrow range of frequencies but with open wire feeders, you can operate on every frequency above the design freq of the antenna.  SWR?  Never a problem, since -- unlike coax -- open wire line has almost zero loss even with insanely high SWR present.

If you look hard, you'll spot the fact that there are not one but two eight foot ground rods.  I had a contractor in to do some other work on the house and I puzzled him into a frenzy by asking him to purchase and ram in those two ground rods.  Glad I did; they work great.  Every piece of equipment in the shack is bonded to one or the other of the rods, by way of the straps that you can see in the photo.

The knife switch at the top of the pic is to shunt the feeders to ground, whenever I learn of any storms in the area.  The "up" position is for normal antenna-to-rig(s) operation, while the 'down' is everything-gets-grounded ops.

If you have any questions about what you see in the picture, ask away.  Some of you might want to know just how the feeders get where they're supposed to go, all the way to the tippety-top of the antenna mast.  Or maybe you want more info on the antenna system tuner.  Just don't ask me how much that sucker costs.  Anytime the XYL asks me about that matter, I claim domestic forgetfulness.

73

Luck, WA4STO
ARRL A1-Operator
NTS(D) Target Station
NTS(D) Digital Relay Station

Are your 2 ground rods bonded together ?  Are they also bonded to you house service ground ?  If not they need to be both for safety and to meet electrical codes where all grounds must and should be bonded together.

Quote from: Geek on April 13, 2013, 09:08:53 PM
Safe camping requires a minimum of three people.  If one gets hurt, then one can go get help, while last renders assistance.  That point leads me to the fact you didn't list a first aid kit.  I hope that is among the stuff not worth mentioning, along with map and compass.

I've roamed the woods for may a year now, solo, and never once do I remember ever taking along a map.  I always have at least a small button compass but never saw the need to use it.  But then most of the places I go I am very familiar with just through my own exploration.  I do it the old fashioned way by marking the trail as I go, ie, I break a small branch, carve marks in dead trees or logs, pile up rocks or sticks, just anything to mark where I've been and then just follow my marks back to where I started.  And I always carry a survival kit with means to carry and purify water, start a fire, and build shelter and it also includes a good first aid kit.  And thats one piece of kit I'm proud to say I've never had to use so far in my 57 years - but it will always be there if needed !

Quote from: IZ2UUF on October 16, 2013, 09:05:45 AM

Quote from: Lamewolf on October 16, 2013, 08:30:06 AM
I agree with everything you said, but I do know that onece I switched to balanced feedline, all my RF problems ceased.  With the coax fed antennas I was using, nothing I did seemd to help at all.  I used ferrite beads on everything, 1:1 current baluns at the feedpoint of my antennas, multiple grounds rods all bonded together, nothing seemed to help.  The problem wasn't all that bad, but it was there in the form of RF on your audio reports constantly.  Then one day when experimenting with a doublet fed with balanced feedline, a friend told me to take down all my other antennas and use that one because my RF problem was gone !  I've never used coax on a doublet since !  I do use an unbalanced tuner, but I don't use the built in 4:1 balun.  I do have a 1:1 current balun right outside the shack with about 6 feet of coax entering the shack and connecting to the tuner.  The antenna is a 40 meter extended double zepp 178' long and fed in the center with 450 ohm window line about 40' long and via the tuner it will work 10 thru 160 meters.  I also have a homebrew Zmatch tuner Iuse sometimes but that requires running the balanced feedline all the way in, but either way I don't have the RF problems I had with a full coax feed.

I bet it works, you did one of the best and most efficient wideband antennae you could make!
Your setup is very smart, since you are not using the internal 4:1 balun but you placed a choke-balun between the tuner and your rig.
Also, you are feeding your doublet at its center: thanks to this, currents will be balanced enough to avoid line radiation.
However, even though there might still be some unbalance on the line due to real-world differences between the two arms, the choke-balun will stop any common mode current that could run to your rig.
Therefore, the little unbalanced currents that still might be running on the balanced line will never reach your rig, as you experienced.
At home I have the same setup you have and I'm extremely satisfied.

73 de Davide IZ2UUF

I had a 135' doublet setup the same way before I made the 40M EDZ, and when I switched to the EDZ, folks that I normally talked to on 75 meters thought I had bought an amp !  I never run more than 100 watts and even prefer QRP when on CW, but the EDZ made such a big difference in my on the air reports over the 135' doublet, I could hardly believe it !  It is a good antenna for all bands if you only have room for one antenna !

Quote from: RadioRay on September 22, 2013, 08:26:05 PM
Reminder: every Sunday there is a net held in SSB (apparently voice can be sent over radio - who knew?) Right now the freq is 'around' 7242LSB, depending upon interference.  It will move UP the band to find a clear spot.  Net control is Ruth, whose voice is easy to find on a band filled with grumpy old men.   >:( >:( >:( >:( >:( >:(  :-*  >:( >:( >:( >:( >:( >:(


'SEE' you on the radio.  This is the one time per week I am in voice on the radio.


de RadioRay ..._ ._

What time UTC are the nets ?

Quote from: IZ2UUF on October 16, 2013, 05:29:12 AM

Quote from: Lamewolf on October 10, 2013, 01:56:41 PM
There is no need to worry about RF in the shack from balanced feedline, since it is balanced, the fields in the feedline cancel each other.  Coax on the otherhand is more likely to radiate RF unless some means of choking is used to keep RF off the outside of the shield, ie: current baluns, RF choke, ferrite beads.  I call the problem of RF on coax the "3rd wire syndrome", you have the inner conductor, then the shield, and then the outside of the shield that does sometimes look like a 3rd wire to RF !

Well, actually you might still have RF in the shack even from balanced feedlines. This happens if load is not balanced: currents in the feedline would not be the same and they would not cancel. In this case, we would need a balanced tuner, i.e. a tuner able to force equal currents with 180° phase even on unbalanced loads.
This is a good reason to aim to symmetrical aerials, like the dipole I have described.
The balanced/unbalanced tuners on the market (like many MFJs) force balancing by mean of a 4:1 wideband balun: ANT->LINE->BALUN->TUNER->COAX->RIG.
The problem is that the BALUN, at that position, is working where SWR is very high, reducing its efficiency.
There are some tuners (like Double-L Networks) that are able to force equal currents by design without the balun workaround. However, using a balanced antenna, i.e. offering the same impedence on both sides (electrically symmetrical), we can use ANT->LINE->TUNER->BALUN->COAX->RIG, where the BALUN can be a simple choke. In this case, the TUNER does not need to be balanced, since currents are balanced by themselves due to the symmetrical load.
If COAX is short and RIG is not grounded, the path COAX->RIG is so short that its impedance at HF frequency is very high, so we can get rid of the BALUN. This becomes a very simple setup.

I also would like to add some calculations about efficiency of the whole system comparing a 16m long horizontal dipole fed with 20m of 450 ohm window line and a tuner and two resonant single-band dipoles in 20m and 15m fed by 20m of RG-213 without tuner, all mounted at 10m on the same ground.

• radiation diagrams and antenna feed point calculation is done using 4NEC2;
• feedline impedance transformation and loss over mismatched load is done using Transmission Lines Details 2.0 by AC6LA;
• tuner dissipation is calculated using T-Network Tuner Simlator by W9CF; its calculated results match pretty closely the measurement I made myself on my tuners;

This is the situation at 14 MHz (multiband dipole is red, monoband resonant dipole is blue):



Non resonant 16m-long dipole
Impedance ad feed point: 449+j1044 
Transmission line 20m 450-ohm: loss 0.21 dB 
Impedance at tuner: 1910.240+j1477.946
Tuner loss: 0.3 dB
Total antenna system gain: 6.32-0.51 = 5.8 dBi

Resonant 14 MHz dipole
Impedance ad feed point: 73.1+j0       
Transmission line 20m RG-213: loss 0.46 dB
Total antenna system gain: 5.62-0.46 = 5.16 dBi


This is the situation at 21 MHz (multiband dipole is red, monoband resonant dipole is blue):



Non resonant 16m-long dipole
Impedance ad feed point: 499+j1534 
Transmission line 20m 450-ohm: loss 0.430 dB 
Impedance at tuner: 5057.142+j288.847
Tuner loss: 0.5
Total antenna system gain: 8.81-0.5-0.43 = 7.88 dBi

Resonant 21 MHz dipole
Impedance ad feed point: 70.7+j0       
Transmission line 20m RG-213: loss 0.544 dB
Total antenna system gain: 6.37-0.544 = 5.826 dBi

These figures seem to prove that some very common ham myths like "the ideal solution is a single-band resonant dipole, multi band dipoles are just compromises", or "a tuner will dissipate most of your power" are just... myths.
A setup made of a longer dipole, open-wire and tuner outperforms any single band tuned dipole on a frequency range of about F to 2*F, where F depends on the length of the non-resonant dipole.

73 de Davide IZ2UUF

I agree with everything you said, but I do know that onece I switched to balanced feedline, all my RF problems ceased.  With the coax fed antennas I was using, nothing I did seemd to help at all.  I used ferrite beads on everything, 1:1 current baluns at the feedpoint of my antennas, multiple grounds rods all bonded together, nothing seemed to help.  The problem wasn't all that bad, but it was there in the form of RF on your audio reports constantly.  Then one day when experimenting with a doublet fed with balanced feedline, a friend told me to take down all my other antennas and use that one because my RF problem was gone !  I've never used coax on a doublet since !  I do use an unbalanced tuner, but I don't use the built in 4:1 balun.  I do have a 1:1 current balun right outside the shack with about 6 feet of coax entering the shack and connecting to the tuner.  The antenna is a 40 meter extended double zepp 178' long and fed in the center with 450 ohm window line about 40' long and via the tuner it will work 10 thru 160 meters.  I also have a homebrew Zmatch tuner Iuse sometimes but that requires running the balanced feedline all the way in, but either way I don't have the RF problems I had with a full coax feed.

Quote from: gil on April 03, 2013, 02:47:29 PM
Thanks Bob, great info!

I figured that on 80m, losses can have an impact. Not like on 20m.. The band is noisy and every bit helps.
I might have to rethink my potting plans then.. Maybe something closer, like closed-cell foam.
My idea was to find some kind of mylar for extra insulation between the coil and the case.

Gil.

Just wrap the coil in teflon pipe tape, its a good insulator and holds up real well to high voltage !

Quote from: cockpitbob on October 15, 2013, 01:14:02 PM
That design looks similar to the mag loop tuner MFJ sells. 

If it's less fussy to tune between bands that has a lot of appeal since everything is at the bottom of the loop. 

Where did you find the dual gang cap?

I collect radio junk, so the caps in my loop tuner came from my junkbox and they originally came from an old receiver.  But the tuner does use the same layout as the MFJ does but mine doesn't seems to be "fussy".  All I do during tuneup is to tune the dual gang cap for maximum signal or noise level then use the single gang cap to fine tune the swr, then I tweak each one for best match.  The thing I like about the tuner is that the loop doesn't need a seperate feedloop, all the controls are at the bottom, and you can change the loop size depending on what bands you want to work.  Mine is mounted in a small aluminum box from Radio Shack and with a few different lengths of wire I can work all bands 10 thru 80 meters.  Also, I might add that you can make a nice support for the loops from normal PVC pipe.  I have built and used magloops from soft copper tubing, but the thing I like about the Army Loop Tuner is that it will all break down and fit in a brief case along with my Icom 703 and other related gear.

If you guys want a portable loop for qrp use, try the "Army Loop Tuner" in the attached schematic.  No feedloop needed and you can attach different sizes of loop depending on what bands you want to cover.  I built one for use from motel rooms and with up to 10 watts from an Icom 703 I have worked all over the world using a simple wire loop of about 4' square.