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Topics - radiozed

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Equipment / The hidden mag loop antenna
« on: January 12, 2017, 1601 UTC »
I've been off the air for awhile, but hope to get back up and running soon.  A couple of months back I was encouraged by an east coast report while running my ugly mag loop antenna at just 40 watts.  I decided to make something a little better, but was still stymied by HOA rules that forbid any sort of visible antennas.  While I know that mag loops can have decent performance on the ground, I also knew I could improve things if I could just get it up in the air just a bit.  But I needed it to be stealth enough that nosy nellies wouldn't ask too many questions.  Enter my version of the "stealth" mag loop:


Just under 4' diameter, constructed of 3/4" copper pipe.  Haven't tried it on the air yet but my antenna analyzer likes it just fine.  It's enclosed in a plywood box that will be painted the same color as my house.  I figure I'll mount it 4-5' up on the side of the house (if my wife will let me).  If not, I'll mount it out on a large trellis in the backyard.  In either case it should blend in and not draw too much attention.  If anyone asks what it is I'll just say, "It's a wood box.  You've never seen one?"   ;D

Broadcast Announcements / Radio Zed broadcasting on 6925 USB
« on: November 07, 2016, 0223 UTC »
Right now.   ;)

Broadcast Announcements / Radio Zed broadcasting on 6925 USB
« on: October 11, 2016, 0306 UTC »
right now

Broadcast Announcements / Radio Zed broadcasting on 6925 USB
« on: September 30, 2016, 0142 UTC »
right now  ;)

Broadcast Announcements / Radio Zed
« on: September 26, 2016, 0214 UTC »
Radio Zed is currently rocking some decidedly non-big band music on 6925 AM at the moment.  ;) 

Broadcast Announcements / Radio Zed testing on 15070 khz USB
« on: September 19, 2016, 0124 UTC »
On and off for a little bit

Broadcast Announcements / Radio Zed testing on 15050 khz USB
« on: September 04, 2016, 1915 UTC »
Testing right at the moment on 15050 khz USB at about 50 watts.  Will be on and off in short 10-15 min snippets of broadcasts this afternoon while testing out a new setup. 

Equipment / need help wiring ACC connection from radio to amp
« on: August 27, 2016, 0305 UTC »
I have a Yaesu FT-817 and I recently purchased a 45 watt QRP amp to use with it.  The amp came with an ACC cable to connect to the back of the 817, but unfortunately they didn't connect the actual ACC plug that goes in to the back of the Yaesu (either that or it fell off during shipping).  The ACC cable coming out of the back of the amp has just two wires, one red and one black.  Here is the wiring diagram for the ACC port on the Yaesu 817:


So I guess what I'm looking for is where I connect the red and black wires on the ACC plug.  Any advice would be appreciated! 

General Radio Discussion / 40 m dead carrier curiosity
« on: August 24, 2016, 1538 UTC »
This past weekend I took the family out to the country where I had rented a quaint turn of the century (19th century) farmhouse out in the middle of nowhere.  Nearest neighbor a mile away, no Internet or television, no cell phone coverage...it was a great few days of unplugging from everything and forcing the kids to tune in to, you know, reality.   ;D  One of the few tech things I brought along was my Grundig radio so I could do something I haven't in a very long time...some SWL. 

While scanning the bands one night, I came across something odd in the 40 meter band.  It was a dead carrier that pegged the Grundig at S9 and it ranged from around 7200 khz up to 7300 khz (I didn't make a note of the exact start/stop).  It was there the entire 3 days we were at the farmhouse.  That makes me think it was coming from somewhere in the house (or out in one of the barns that were on the property) as opposed to some area Ham who had inadvertently left something keyed on their rig.  It was an absolutely silent carrier, no hint of background noise, no static, no tones...nada. 

Anyway, I was curious what would cause something like that.  I've never experienced a signal like that before when SWL.  Maybe it's a phenomenon some here are more familiar with. 

I'll be giving a try on 15050 khz in a few moments in USB or AM.  Power will be at QRP levels, so don't expect anyone to hear...but thought it would be helpful to have a few people at least listening.   ;D

Maybe an impossible quest, but I thought if anybody would know it would be some of the experts here.  Early next year I'll be embarking on an expedition where I'll be spending a couple of weeks on one of the highest mountains in the world.  I thought it might be a good opportunity to try some high altitude broadcasting with nary an obstruction anywhere in sight.   ;)  I haven't decided on what radio to take yet (right now thinking of taking one of Stretchy's Lulu transmitters, but may also take along my Yaesu FT-817 so I have some wider frequency/mode options).  In whatever setup I use, I wouldn't plan on broadcasting at more than 40 watts.  So here are my limitations:

- has to be lightweight and fit in to my backpack

- dipoles are out of the question.  being on a mountain like where I'll be, there would be nothing to attach it to.

- has to be fairly stealthy.  Yes, I'll be on a remote high altitude mountain, but so will a lot of other climbers.  Since there isn't much in the way of 21st century technology to keep climbers entertained (except maybe their ipod), people still tend to pass the time by listening to AM/FM/SW radio.  The last thing I want is to have one of the 300 or so climbers in basecamp (not to mention the dozen or so park service rangers) coming across my signal and then simultaneously noticing the one North Face tent with the 8' vertical propped up outside of it.   ;D  For this reason, something like a hamstick dipole probably isn't the best idea either. 

With these limitations in mind, about the only thing I've found so far is this:

http://www.eham.net/data/classifieds/images/263735.jpg  (the MFJ-1899T)

Seems like it would fit the bill.  I could broadcast from inside the tent and run the antenna up through the vestibule zipper and nobody would probably be the wiser, especially after dark.  Yes, I know from reviews that they're not known to be especially efficient, but I'll be up over 7000 meters so I think my signal should still get out fairly decent.  The one problem I see is that it'll only handle 25 watts max.  Maybe if people don't think I'll need anymore than that I'll stop obsessing and just take it along.  The other limitation I see is that this little guy (as well as the similar "Miracle Whip" antenna) are typically said to require some random length of counterpoise to have any hope of getting a decent signal out.  If it's unavoidable, it's unavoidable and I'll just have to deal with it.  I just have this fear of stringing out 18' of thin copper wire and either having someone trip over it (crampons will trip you up on just about anything if you're not careful) or having someone notice it and say, "hey, what's this?" and pick it up and risk getting an RF burn. 

One last alternative I've thought of would involve building my own.  Take two 2' lengths of fiberglass pole with a threaded connection in the middle.  Hand wind it with copper wire and cover said wire with black tape.  Unscrews in the middle for easy packing.  Get in to camp and screw the two ends together and I have a 4' vertical.  Put a fake handle on the top and a snow basket on the end and it looks no different than the hundreds of ski poles that other climbers have propped up outside their tents.  Downside is I'd certainly need to take a tuner along and it would probably still require a counterpoise of some sort.  Not perfect, but maybe doable.  Could probably handle far more than 25 watts too. 

Any other ideas from group?

Equipment / Effects of modification to gutter antenna
« on: July 02, 2016, 1717 UTC »
Question for the experts here as I don't have access to antenna modeling software (nor would I know how to use it).  I'm currently broadcasting off an approximately 40' long aluminum gutter mounted about 25' up on the side of my house.  One end points due north and one end points due south.  Coax is connected via 25' high aluminum downspout.  Coax shielding connected to about a 40' long counterpoise stretched across the back yard.  Whether this setup behaves more like an inverted L, or a dipole, or simply a vertical...I'm not really sure. 

In any case, my reception reports seem to be mostly directional to the east of me, with some reports to the north (but it's a pretty close station).  On the north side of my house I also have an aluminum gutter that's about 30' in length.  I've been thinking of getting up on the roof and running a wire from the north/south gutter to a connection on the east/west gutter.  Mostly as an experiment, but also just to see if it makes my signal a little more omni-directional.  For you folks who understand antennas far better than I do...any idea whether this modification would do anything for me?

Equipment / worrisome symptoms from recently repaired Ameritron
« on: June 28, 2016, 1556 UTC »
A few months back I purchased a new Ameritron AL-811 600 watt amplifier.  Life was good for a couple of months until one evening it just "popped."  "Popped" meaning I seemingly blew it up.   ;D  The lights in the house flickered, there was a loud "pop" from inside the amp, and then the strong smell of electronic circuity burning as it died.  Not good.  Fortunately it was still under warranty so I sent it back to the good folks at Ameritron for some work.  They fixed it up good as new (still not sure all that they did, but I know they replaced the tubes) and sent it back.  I asked for their advice on how to keep this from happening in the future and they replied with a sort of generalization of "never use AM, make sure it's tuned up properly, and don't overdrive it."  (a slight off topic rant...I don't use AM, but why do they like to advertise that the 811 can handle "400 watts AM"?)

So, I've had the unit back for awhile and things have been going well.  However, the last two broadcasts I've noticed some strange symptoms from the Ameritron that came on quite suddenly.  The 811 is humming/buzzing loudly, in perfect oscillation with the broadcast.  When I listen to my broadcast on a remote SDR monitor, I can notice a faint "warble" to the broadcast that coincides with when the 811 is humming/buzzing the loudest.  Also, it's heating up much more rapidly than it used to.  Before the blow out, I could key down for 45 minutes before it started feeling what I'd call "really" warm to the touch.  Now it's getting pretty hot after 20 minutes or so.  I never run more than 450-500 watts, I'm tuned up as good as I can, and I'm showing an SWR of just barely over 1:1.  The 811's fan seems to be working perfectly. 

Right now I'm tempted to keep it shut down until I figure out what's causing these symptoms.  The last thing I want to do is blow it up again (yes, warranty is still in effect, but I still have to pay the $70 shipping to get it there).  Anyone have some advice?  Am I simply overdriving it?

I took some time away from broadcasting back in early May following a significant equipment failure.  At that time, I was still managing to get decent reception reports from the East Coast and even a smattering in Western Europe at times.  But when I came back in the middle of June, band conditions had definitely changed.  Most times when I tune up 43 meters on the Arizona SDR I use as a monitor, all I hear is what sounds like a steady and super fast "tapping" (OTHR?).  The 43 meter waterfall pretty much looks like a blizzard is hitting it from left to right.  Even when I'm not getting this interference, I'm barely audible on the SDR (when before I was always a blowtorch in to AZ).  Reception reports across the rest of the country are spotty, typically not getting out much farther east than the mid-west. 

I wasn't around the scene last summer, so I'm just trying to determine if this is a taste of what's to come for the rest of the season?  Should I just throw a cover over everything and take a break until the winter cold returns? 

Broadcast Announcements / Radio Zed
« on: June 13, 2016, 0226 UTC »
Since I can't seem to compete with "All Pogo All the Time" on 6925, I'm currently giving it a go on 6930 USB.   ;D

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Item image   Antenna Impedance Matching by Wilfred N. Caron - ARRL