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Locked New to Group- Ferrite Antenna Question
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Hi All-
Just discovered the group. Also just discovered NDBs! I have a Grundig YB 400 PE and Radio Shack DX-399- both with only ferrite antennas. Am studying various loop options, but wondering if the expertise of this group can recommend a basic, easy to make homebrew that is worth trying to augment the ferrite rod antennas (no external jack for LW). Basically, want to start experimenting, but with an easy project proven to help these portable rigs. Any thoughts? Thanks much- Lee KC2IYK |
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Steve Ratzlaff
Hi Lee,
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DXing LF beacons has been a radio interest for me for many years, but I've always used tabletop receivers and outdoor antennas. Local noise is the main problem most folks have when trying to hear anything at LF. And with your portable radios which aren't particularly sensitive at LF with their small internal ferrite rods, along with no provision for an external antenna input--you have a challenging goal. And if you're limited to an indoor LF antenna, that makes it harder as well. I don't know of any basic, easy LF antenna projects to suggest. You might consider a large 4-5 foot diameter tuned loop which you could set your radio inside of--that would greatly improve the LF sensitivity, as long as the local house noise didn't overwhelm weak signals. But you'd have to experiment with number of turns and variable capacitor value in order to figure out where resonance at LF would be. That could be quite a trial and error process. Or you could try building the loop antenna list member Al has recently mentioned on this list in the past week, and leave off the coupling part--setting your radio inside the loop. He's already come up with a proven LF tuned loop. His recent messages give info about his loop--check the message Archives if you are really new to the group. 73, Steve NE Oregon ----- Original Message -----
From: "Lee H. Badman" <lbadman@...> To: <loopantennas@...> Sent: Thursday, March 08, 2007 5:43 PM Subject: [loopantennas] New to Group- Ferrite Antenna Question Hi All- |
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Radio Plus makes the Q-Stick+ <>, which is
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a tunable, large ferrite antenna that covers LW and MW. I've used mine with my DX-398 on LW. It's not going to get you exactly world class reception, but it's a huge improvement over the small built in ferrite antennas in most radios. If you don't want to spring for a pre-made one, you could maybe run with the basic idea. Get a big piece of ferrite, some magnet wire to wind around it, and a couple air variable capacitors, and then start experimenting. -- Jay On 3/8/07, Lee H. Badman <lbadman@...> wrote:
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Jim Dunstan
At 01:43 AM 3/9/2007 +0000, you wrote:
Hi All-Hi Lee, The easiest way to get started with a LW or MW loop with the kind of receiver that uses an internal ferrite loop antenna is to build a tuned loop and couple it to the receiver through mutual induction. The YB400 is small enough it can mounted on the same base as your tuned loop. So all you need to do is make a loop frame ..... usually of wood .... of a reasonable size .... I would say at least 2' in diameter. Get some flexible wire ... almost any kind will do ... wind about 15 to 20 turns on it. Mount a single or double gang receiving type capacitor somewhere convenient on the loop frame and use it to resonate the loop at the frequencies of interest. Add or remove turns to get the desired frequency coverage. Adjust the orientation and location of the small receiver ... eg the YB400 for best reception .... eg best nulls. You are in business. Jim |
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