Re: [Elecraft] EFHW

I've used that too, but if one wants to use it on other bands the tapping on the "tank" to match the impedance and the position or turns on the link can become tricky. An "L" network, when feeding a high impedance load such as an EFHW, is also a "tank" circuit with the antenna on the "hot" end.

Re: [Elecraft] [KX3] Lithium Battery Video

In the late 1800's, refineries producing kerosene burned any "gasoline" byproducts as dangerous waste - the same stuff we use in pre-Tesla automobiles today. The reason was that gasoline was "obviously" ar too dangerous for consumer use. Kerosene, with its much lower volatility and lower heat per

Re: [Elecraft] EFHW

The classic way to feed a EFHW is to use a tuned tank circuit. The top of it goes to the antenna and the bottom goes to a short counterpoise or the coax shield. You can either tap the coil X turns from the bottom to match 50 ohms or use a link coupling with the appropriate number of turns. I

Re: [Elecraft] [KX3] Lithium Battery Video

On 2/8/2017 6:46 PM, Fred Jensen wrote: www.livescience.com/50643-watch-lithium-battery-explode.html Excellent, thanks much! Very enlightening viewing. thanks much and 73, Ben, KD5BYB __ Elecraft mailing list Home:

Re: [Elecraft] EFHW clarification

Guess I missed that in your post, sorry. Any conductor of any length will radiate, resonant or not ... provided you can get your TX to feed power into it. In all cases, the far end of the conductor is an open circuit [High E, low I, High Z] The impedance at the feed end will be a complex

Re: [Elecraft] [KX3] Lithium Battery Video

http://www.pbs.org/video/2365946428/ On 2/8/2017 18:24, Ben Hall wrote: For anyone who would like to know why Lithium batteries can be so dangerous I ran across this interesting video from PBS Nova. If you have Would someone be so kind as to mail me or repost the link? For some reason, I

Re: [Elecraft] EFHW clarification

The low current in the counterpoise or ground system is the main advantage of an EFHW over a random wire. (A random wire "close" to a half wave will have a similar radiation pattern, but much higher ground system current.) The feedpoint impedance of the EFHW can be 1500 to 5000 Ohms. With a

Re: [Elecraft] EFHW

If you are planning to use the autotuner in your KX3 or KX3, I'd strongly recommend the random wire. I work on the basis that there is no "passive" device. Anything between your finals and the 'aether' is either a gain device (external amp) or a loss device (transformer or "balun", transmission

Re: [Elecraft] [KX3] Lithium Battery Video

I think you're referring to: www.livescience.com/50643-watch-lithium-battery-explode.html 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 2/8/2017 4:24 PM, Ben Hall wrote: For anyone who would like to know why Lithium batteries can be so dangerous I ran across this interesting

Re: [Elecraft] [KX3] Lithium Battery Video

I've been a bit Leary of LiPo batteries since I used to fly Electric RC helicopters. They can be quite volatile  From: Doug Person To: elecraft@mailman.qth.net Sent: Wednesday, February 8, 2017 6:41 PM Subject: Re: [Elecraft] [KX3] Lithium Battery Video I had a

Re: [Elecraft] EFHW clarification

I would suggest, a good coax choke also.  Cheap easy and good insurance.  The real problem of the 9:1 un un is that IF the transformer is not balanced, there will be CMC to deal with.  Mel, K6KBE From: Dan Presley To: K2 Sent: Wednesday,

Re: [Elecraft] [KX3] Lithium Battery Video

For anyone who would like to know why Lithium batteries can be so dangerous I ran across this interesting video from PBS Nova. If you have Would someone be so kind as to mail me or repost the link? For some reason, I didn't get the original post with the link, and its not in the archives

[Elecraft] EFHW clarification

Thanks for the replies so far. Just to clarify-I plan to use the built in auto tuners in my KX2 and 3, so hopefully they can handle the job. I already have a good 9:1 transformer which should work. The primary question is the advantage to the EFHW as opposed to a true random length (not a

Re: [Elecraft] [KX3] Lithium Battery Video

I had a poor quality Lithium-ion pack explode with the force of dynamite while recharging. Shrapnel was embedded in the sheet rock 8 feet away. The shock wave was so intense, it ruptured my left eardrum. I never considered that they could be dangerous. Now I know by finding out the hard

Re: [Elecraft] EFHW

I have two EFHW antennas. One covering 40 and 20; the other 17. They are mounted at about 40 feet and perform equal to regular dipoles. Feeding them is therefore much simpler for portable ops since only one side needs to be elevated. For portable use I feed them with about 20 feet of RG/58a,

Re: [Elecraft] EFHW

Two distinct advantages of the EFHW: It's high feedpoint impedance means a minimal counterpoise is required and very little power is wasted into the ground system. Second, the high current part of the wire, which does most of the radiating, is a quarter wave from the feedpoint, which can

Re: [Elecraft] EFHW

I suspect you're going to get a lot of opinions on your question [end-fed half waves], and a lot more on subjects well removed from your questions ... such is the behavior of lists. [:-) Any half-wave wire fed at the end will present a very high impedance [multiple K-ohms] and will require

[Elecraft] EFHW

Wanted to get some thoughts from folks about pros and cons of an end fed half wave for portable/SOTA use, as opposed to just using a random length wire with a counterpoise connected directly to either the KX2 or 3.(I think Eric recommended somewhere around 28’ depending on the band coverage).Is

Re: [Elecraft] KX2: mini-banana plug

The Pomona 2945-0 uses a set screw to secure the wire. Pomona 3690-0 and 4617-0 also fit the KX2 but the wire is soldered to the plug. 73, Bob N7XY On 2/8/17 1:08 PM, Stephen Prior wrote: Further to my previous message, thanks to Ben W4SC, I have identified the plug I need. For UK

Re: [Elecraft] KX2: mini-banana plug

Further to my previous message, thanks to Ben W4SC, I have identified the plug I need. For UK readers, put Pomona 2945-0 into your favourite auction site and you will find several at decent prices. 73, Stephen G4SJP On 8 February 2017 at 16:13, Stephen Prior wrote: >

Re: [Elecraft] strange request ,,,,, contacts tonight ?

I'll listen on your 40m freq as 20 will be dead here in the Chicago area at that time. Gene N9TF - Original Message - From: Bill Steffey NY9H To: Elecraft@mailman.qth.net Sent: Wed, 08 Feb 2017 19:12:34 - (UTC) Subject: [Elecraft] strange request , contacts

Re: [Elecraft] strange request ,,,,, contacts tonight ?

Button and knob too hard, please make stick.. -Original Message- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bill Steffey NY9H Sent: Wednesday, February 08, 2017 2:13 PM To: Elecraft@mailman.qth.net Subject: [Elecraft] strange request , contacts tonight ?

[Elecraft] strange request ,,,,, contacts tonight ?

for our radio room at our local club ( Washington Amateur Communications - WACOM) we secured a used K3...added the 100 wt amp and away we go, We've used members 5 K3s radios at field day successfully, however some club members have accused me of drinking too much purple 'koolaide" and that

[Elecraft] Solution:Preventing serial port activity during windows boot.

Hi, While researching using a serial port for DTR handshaking on the K3 I saw a number of posts about the K3 going into transmit when a computer boots up. Last night, I found a solution, at least for any USB to Serial device that uses the FTDI chipset (which you should use). If you open the

[Elecraft] KX2: mini-banana plug

Had my KX2 some days now and very pleased with it. I thought I would buy some mini-banana plugs for the counterpoise, but they are too small to properly fix in the hole provided. I had assumed that the KX2GNDPLUG would be a standard size. Postage from USA makes for a very expensive little item.