Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:
The Satellit 800, the Tecsun PL-880, and two indoor antennas – an afternoon of experimentation
By Jock Elliott, KB2GOM
A search for “shortwave listening antennas” on the internet landed me on the page for the Par EndFedz® EF-SWL receive antenna, which is a 45-foot end-fed wire antenna connected to a wideband 9:1 transformer wound on a “binocular core” inside a UV-resistant box. A link on the page invited me to check out the eHam reviews of this antenna, which are here. What struck me is that there are just page after page of 5 star reviews of this antenna. Hams and SWLs apparently just love it. (If you want to buy of these antennas, they are now sold by Vibroplex and can be found here.)
As I reached for my credit card, I remember that I had an LDG 9:1 unun transformer lying around and some wire left over from the Horizontal Room Loop project. Maybe I could create my own end-fed SWL antenna by wrapping the wire around the perimeter of the room, attaching it to the 9:1 unun and then by coax to the back of my Grundig Satellit 800.
So I did exactly that. The wire for new end-fed antenna travels the same route around the perimeter of the room as the horizontal room loop. The main differences between the two antennas are that the end-fed is not a loop, and it terminates in the 9:1 transformer, which, in turn, feeds the Satellit though a coax cable. But in essence, we’re talking about two indoor wire antennas that are the same length and laid out along the same path about 7 feet in the air around the interior of the 8-foot by 12-foot room that serves as a library and radio shack: the horizontal room loop and the indoor end-fed.
The Satellit 800 has three possible antenna inputs: the very tall built-in whip antenna, two clips on the back of the 800 where the horizontal room loop attaches, and a pl-239 coax connector where the new end-fed antenna attaches. In addition, there is a three-position switch that allows me to quickly switch from one antenna to another.
Tuning up on the WWV time stations on 5, 10, 15, and 20 MHz and sliding the switch on the back of the Satellit 800 among the three different positions, I quickly found that the whip antenna was the noisiest of the three choices and offered the poorest signal-to-noise ratio. The comparison between the horizontal room loop and the indoor end-fed antenna was very, very close. While the horizontal room loop was quieter, it seemed to me that the signal offered by the indoor end-fed antenna was the tiniest bit easier to hear, so I decided to leave the Satellit 800 hooked up to the indoor end-fed antenna.
The 100-foot indoor end-fed antenna
Then I did something I had wanted to do for quite a while: I disconnected the horizontal room loop from the back of the Satellit 800 and attached one end of the wire to the indoor end-fed. So now, I had a roughly 100-foot end-fed antenna wrapped twice around the room.
Before we proceed any further, you need to understand this: my comprehension of antenna theory is essentially nil. As the old-timers would have it: you could take the entirety of what I understand about antenna theory, put it in a thimble, and it would rattle like a BB in a boxcar.
Ever since the successful creation of the horizontal room loop, I had wondered: if 50 feet of wire wrapped around a room improves the signal, would 100-feet of wire improve the signal even more? Inquiries to several knowledgeable people produced the same result: they didn’t think so.
Guess what? They were right . . . entirely and completely right. Tuning to the time stations and attaching and detaching the extra 50 feet of wire from the indoor end-fed, I saw (on the signal strength meter) and heard no difference in signal strength or signal-to-noise ratio.
The PL-880 and Satellit 800 comparison
So now, the Satellit 800 is attached to the indoor end-fed antenna, and there is an extra 50 feet wire wrapped around the room on the same path as the end-fed. Wouldn’t it be nice if I could find a way to hook that extra wire up to my Tecsun PL-880?
An old auxiliary wind-up wire antenna from a FreePlay radio came to the rescue. It was an annoying piece of gear; the wire was difficult to deploy and even more difficult to wind up again, and it had languished in a drawer for more than a decade. But it had a really nifty clip on the end that was designed to easily snap on and off a whip antenna.
Pulling an arm-spread of wire out of the reel, I cut it off, stripped the wire, attached it to the end of what had been the horizontal room loop, and clipped it to the whip on the PL-880. Tah-dah . . . instant improvement to the signal coming into the PL-880.
Some time ago, a reader had asked whether I found the Satellit 800 a little deaf in comparison to the Tecsun PL-880. Now, with two indoor antennas of approximately the same length and routed along the same path, I could do the comparison on shortwave frequencies. Starting with the time stations and later with hams in single-sideband on the 20-meter band, I alternated between the two radios. Although the PL-880 has more bandwidth choices, and the two radios have a slightly different sound to them (probably, I’m guessing, due to differences in their circuitry), the bottom line is this: anything I could hear with the Satellit 800 I could also hear with the PL-800 . . . and vice versa. (Note: I did not do any comparison between the two on medium wave or FM.)
In my not-so-humble opinion, both offer worthy performance that is improved with the addition of a 50-foot wire antenna, even if it is indoors.
And that brings us to the final point.
A word of caution
If you decide to add a bit of wire to improve the signal coming into your shortwave portable or desktop receiver, do NOT, under any circumstances, EVER deploy the wire where it could come into contact with a powerline or fall onto a power line or where a power line could fall on it.
As Frank P. Hughes, VE3DQB, neatly put it in his wonderful little book Limited Space Shortwave Antenna Solutions: “Make sure no part of any antenna, its support or guy wires can touch a power line before, after, or during construction. This is a matter of life and death!”
And when thunder and lightning threaten, make sure your outdoor antenna is disconnected and grounded.
Hello Jock
Thanks for all of your contributions to the SWLing Post.
“Now, with two indoor antennas of approximately the same length and routed along the same path, I could do the comparison on shortwave frequencies……..
……performance … is improved with the addition of a 50-foot wire antenna, even if it is indoors.”
That certainly has been my experience with my Tecsun PL-880 over the past 6 years. For the first 6 weeks, I used my PL-880 with its whip extended (~100-cm or 39-in.); and found the reception to be quite good across all the broadcast and amateur bands. Based on my experience, I would have to say that Tecsun has optimized performance on the PL-880’s whip antenna.
Having said that, I found the performance can be improved through the use oof indoor wire antennas. I first used the Tecsun AN-06, 5.3 m (~17.4 ft) — supplied with the PL-880. Next I purchased the Sangean ANT-60, 7-m (~23-ft). Both antennas are strung as horizontal room loops in my 15 x 12-ft sun room, which has a fairly low noise environment. Both wire antenas consistently outperform the whip, with the ANT-60 doing a little better than the shorter AN-06.
So, based on my experience, you don’t even need 50-ft. — half that will make a difference.
Cheers & 73
Roger,
Oh, absolutely — you don’t need 50 feet . . . the auxillary antenna that comes with the PL-880 will make a significant difference and is highly recommended . . . by me!
The 50-foot thing came from the original Horizontal Room Loop experiment with the Satellit 800. It’s not a “magic” number or length.
Thanks for the kind words and your comments.
Cheers, Jock
Andrew (Grayhat),
I did your experiment with ground stake. Stay tuned for future posts!
Cheers, Jock
Every QTH is different. What might work at one QTH may not at another. So if you want to experiment, have at it. Don’t let the naysayers stop you. Cebik, one of the best antenna guys, said as much. Regardless of what an “expert” might say. there are very few absolutes in this world. Good article. Thanx. 73.
Bob,
Thanks for the kind words.
You’re right: there is certainly no harm in experimenting, particularly when the cost of doing the experiment is low, and it just might pay off, like it did with the original Horizontal Room Loop. Doubling the length of the wire, not so much, but . . . it was fun to try!
Cheers, Jock
What a great write up! The best SW antenna I ever had was a copper wire that was strung across the peak of my house. It was strung as tight as a guitar string about 1” above the peak and for all intents and purposes invisible.
It was terminated with an old WinRadio 9:1 balun where the copper wire entered the balun and from the balun it went out on a BNC connector which I had an BNC>PL259 connector into my Satellit 800.
https://www.winradio.com/home/lwa.htm
It was very cheap to make and never had a problem in 10 years of Pacific Northwest rain and wind.
It fed into my Grundig Satellit 800. This setup allowed me DXing of pirates for the first time.
The question I have is what would the performance hit of removing the 9:1 balun? The link I provided states that the balun “delivers significant signal strength increase (up to 17 dB in some cases, and approximately 5 dB on average).”
I have the nagging feeling that it would have nowhere near the 5-17dB increase on the Satellit 800’s killer s-meter.
What do you think?
Adam,
First, thanks for the kind words.
Based on my experience, I did not see any “marked” improvement in signal strength or intelligibility with the addition of the 9:1 unun. As I said in the write up: “The comparison between the horizontal room loop and the indoor end-fed antenna was very, very close. While the horizontal room loop was quieter, it seemed to me that the signal offered by the indoor end-fed antenna was the tiniest bit easier to hear, so I decided to leave the Satellit 800 hooked up to the indoor end-fed antenna.”
So that’s it: if someone took away the LDG 9:1 unun, I don’t think it would seriously impact my listening; it delivers a small improvement in “listenability.”
As to the link you provided, if you had seriously UNmatched impedance, perhaps the “long wire adapter” might provide a noticeable improvement in performance; I honestly don’t know. Maybe one of the more technically knowledgeable readers can chime in.
Finally, I love the idea of your long wire, strung tight as a guitar string just an in above the peak of the roof. Talk about “plausible deniability!” . . . “What’s that?” Answer: “Oh, it keeps the birds off the roof.”
Cheers, Jock
“The comparison between the horizontal room loop and the indoor end-fed antenna was very, very close. While the horizontal room loop was quieter, it seemed to me that the signal offered by the indoor end-fed antenna was the tiniest bit easier to hear, so I decided to leave the Satellit 800 hooked up to the indoor end-fed antenna.”
If you want to make an experiment, connect the end-fed to the Satellit high-Z wire input (clamp), then pick a (relatively short) run of insulated wire connect one end of the wire to the high-Z “ground” (clamp) and the other end of that wire to the “gnd” hole in the wall plug
The above being said, I prefer keeping antennas outside and taking care of the feedline, this helps reducing or eliminating noise from indoor appliances like switching PSUs and other things, anyway, if you want, try the above idea and let me know how it works for you 😉
Andrew,
Thanks for the comments.
Thanks to a tree falling on the powerlines, I now know that the inherent electrical noise in my radio room is basically down to the level of atmospheric noise.
Neverthless, experimenting with a ground is definitely worth trying. A thin wire, sneaked out the window to a ground rod, might do the trick. I’ll report back after I try.
Cheers, Jock
Hi Jock
“Andrew, Thanks for the comments.
Thanks to a tree falling on the powerlines, I now know that the inherent electrical noise in my radio room is basically down to the level of atmospheric noise.
Neverthless, experimenting with a ground is definitely worth trying. A thin wire, sneaked out the window to a ground rod, might do the trick. I’ll report back after I try.”
I was serious, try the “wall plug ground” I described, it won’t start any “magic smoke” or the like, otherwise, if you can lay out a wire with a length of 5m max, cut to be NON resonant, and connected to a good ground stake, go for it
Then, if you want to discuss this further, just ask Thomas for my e-mail, I agree to share it with you 😀