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   Home   Help Search  
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 1 
 on: Today at 06:30:57 AM 
Started by KD8GIR - Last post by KD8GIR
I am looking for suggestions for an antenna placement on my house.  I have an R6000 on the back porch (see pic) and it is too close to the house to work.  I am thinking of putting it up on the flat top roof, the flat rectangular space above the two windows.  Do you think that is worth trying?  Any other antenna suggestions? thanks Jeff KD8GIR


 2 
 on: Today at 06:26:16 AM 
Started by K0RS - Last post by W1XYZ
This same problem happened to my MP and was accompanied by other odd things - all resulting in no return to Rx.  I had noticed a small frequency drift and replaced the TXCO, and to my surprise it turned out that the old high stability reference oscillator output was low, and replacing it cured the return to Rx problem. I am not sure why or how these systems could be connected and it makes no sense to me why PTT and VOX would differ in this way, but I thought I would mention it here.

 3 
 on: Today at 06:25:10 AM 
Started by KC8MWG - Last post by KD6RF
We can see the problems that arise when trying to discuss these "end-fed" thingies  Shocked  There's so many variations, lots of hodge-podge and rules-of-thumb, but very little actual design.

The EARCHI type "designs" are a mixed blessing - they're probably responsible for getting thousands of hams out into the field and up at the summits for remote activation with easy to set up equipment!.  OTH, the hodge-podge "design" also has lots of folks thinking that being able to TUNE, and radiating EFFICIENTLY, are the same thing  Of course, they are not the same thing Embarrassed

Unfortunately with these rules-of-thumb: sometimes we use a "counterpoise", sometimes we don't need a counterpoise (which of course isn't true), sometimes we use the coax as the counterpoise, sometimes use a 24 ft wire, no, sometimes we use a 37 ft wire....etc.... This only means that's the "designers" didn't really have a good handle on how these systems work. 

It's also why so many hams are sour on the lower bands.  One is virtually guaranteed to be badly INefficient on the lowest band or 2 that can be tuned with one of the typical EARCHI type end-fed setups.

There's no magic setup - on the lower bands, there's no escaping that a "radiator" wire needs a good RADIAL system when it's length starts becoming significantly less than 3/8 wavelength or so. 

By contrast, many "end-fed" type implementations can be thought of as a "radiator" wire with a single short radial - IOW horribly inefficient, especially on the lower bands.

While an UNUN is a good strategy for the high bands, another mistake often made is to use the UNUN on the lowest band where a loading coil is what is needed.  Almost counter-intuitively, the fact that some of these hodge-podge end-feds can be MATHCHED on the lower bands necessarily MEANS that they are horribly INefficient.

The point is - before bounding off into end-fed-world, first get back to some basics, and realize that's there a bit more to putting out a good signal than just getting the Reflect Power Needle to read zero.  Once we have the antenna actually putting out a good signal, then we can worry about those few dB  lost in a coax cable.




 4 
 on: Today at 06:19:59 AM 
Started by W5KUB - Last post by K8PRG
I'd sit down and
have a cup of coffee with him if we ever met in person. Heck, I'd probably even buy.

73 de N8AUC
Eric


I'm betting it would be a non-stop-bitch-fest...why would you want to subject yourself to that?
If you really wanted to get him started, tell him about how I memorized enough answers to pass my Extra exam...you wouldn't hear the end of it.....

 5 
 on: Today at 06:07:18 AM 
Started by WB7DDI - Last post by KE4OH
Indeed there is no real need for 100W CW. [...]

True.  But it sure keeps getting harder and harder with condx as they are these days....

73   Grin

No gripe with the QRP crowd. But I do like to put out a strapping CW signal. My yardstick is whether or not I can work most of the stations that I can hear. Having said that, I think that 100w or so with a decent antenna is probably the maximum power ever necessary on the lower bands. Less power needed on 20m and above when those bands are open.

HW-16 with and HG-10 VFO is a pretty dang good setup, especially for 80m/40m...

 6 
 on: Today at 06:05:53 AM 
Started by W3TTT - Last post by N3QE
As others have said, most times a J310 will work. They are plentiful and not expensive.

New-manufacture J310's in TO92 were discontinued several years ago.

Since then some distributors have switched over to "Linear Systems" or "InterFET"  J310's in their catalog but they are currently out of stock and over $3 each. Not something you want to use in a new design to replace what used to be a $0.10 part. But OK as an occasional replacment part I guess.

I bought a big stock of J310's a couple years ago when they were announced as end-of-life.

 7 
 on: Today at 06:02:14 AM 
Started by N8FVJ - Last post by K7JQ
My apologies to those who may have been insulted or annoyed by my opinion of Flex as a "cult" radio. By no means am I knocking their radios, as they are definitely one of the best performers, hands down. But I'd be willing to bet that most of their purchasers are quite computer literate, and are drawn to the radios for the tinkering and constant upgrades while (mostly) being tethered to a computer. They're modular in nature...a black box having to use an external GUI or hooked to a computer with a GUI, a mouse or knob module for tuning, or an external expensive Maestro. Hardly mainstream for the great majority of hams that want one self-contained box with all the above included. Yes, their sales are very good, but they pale in comparison to those of the big three, especially Icom and Yaesu, with their multiple offerings.

I believe that SDR based radios are the future for peak performance and economy of manufacturing. Icom has taken it to another level with a self-contained box. Others will follow. And yes, there is a market for the 7851...the guy who wants the biggest and the best at any price...a very limited segment. But if the 7610 comes anywhere near its performance and features, Icom may have to rethink whether it's profitable to continue manufacturing them.

Again, just idle speculation. YMMV.

 8 
 on: Today at 05:50:41 AM 
Started by KN4BBC - Last post by KE4OH
I recommend a coax-fed "fan" resonant dipole. Your 80m/40m/20m dipole will give you 15m for free, because the 40m elements will be 3/4 wave on 15m.

Probably would go with the configuration that gives you the shortest coax run. Just use a decent brand of coax. You choose which kind. At HF, the losses won't add up to a hill of beans.

I personally like a 1:1 current balun as the center insulator. I don't like RF in the shack. I have sometimes had that on certain bands when I didn't use a balun.

Will a dipole work better than your current setup? Who knows? I just like wire dipoles because they nearly always work well and are easy and cheap to build.

 9 
 on: Today at 05:48:28 AM 
Started by VE3LYX - Last post by VE3LYX
AXW I didnt say I was bored. I fractured my spine in a racing accident and while I can still walk some out trips are more then I can deal with now. I also want to do an op in Europe. it is on my buckket list. Floating down the Rhine calling CQ appeals to me. Single band op does not bother me. I often make my HB rigs single band , 80M being my favourite for CW and 40m for AM. Thanks you all for the input.
donVe3LYX

 10 
 on: Today at 05:35:49 AM 
Started by KM1H - Last post by VR2AX
No ballun looks good but I can't see the 20m plot of f/b.

Wyn

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