Tag Archives: Antennas

The Satellit 800, the Tecsun PL-880, and two indoor antennas – an afternoon of experimentation

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.

Video: Frans compares the GRAHN GS5 SE – VLF2 with a large loop antenna

Many thanks to SWLing Post contributor, Frans Goddijn, who shares the following note and video originally posted on his blog:

Mr Grahn of https://www.grahn-spezialantennen.de/ had to stop working for a couple of months (medical reasons) but now he is back and I was able to get one of his highly sensitive Very Low Frequency modules to fit on my Grahn GS5-SE antenna tuner.

As before, the delicate device (“treat like glassware, do not throw”) was extremely well packed for its safe and intact arrival.

Click here to view on YouTube.

Click here to view Frans’ post which includes additional photos. 

Joshuah says: “The Cross Country Wireless LAA++ amplifier rocks!”

Image Source: Cross Country Wireless

Many thanks to SWLing Post contributor, Joshuah, who writes:

Dear Thomas,

I recently dedicated some funding to rebuilding my shortwave listening station.

I had paid attention to new amplifiers  and became aware of some review data by an engineer at SDRPlay comparing amplifier performance that suggests the Cross Country Wireless amplifier, at a cost of only 80 dollars, had become a competitive design offering performance comparable to amplifiers costing 10 times that much.

I was hooked by the specific demonstrations showing that the LAA++ offered IMD characteristics more similar to a Wellbrook, with gain more similar to other high amplification designs. I had to have one.

I set up my station with the following components:

    • A used Icron Ranger 2304 USB over ethernet extender off eBay
    • A used Airspy Discovery off eBay
    • A Cross Country Wireless receiver protector(or similar ferrite + gas discharge diode isolator)
    • A custom ordered LAA++ amplifier from Cross Country Wireless built for 75 ohm with F connectors and a low pass filter at 14MHz
    • A power inserter from an W6LVP that wasn’t cutting the mustard
    • A pair of classic, solid transforming power adapter bricks
    • An unshielded ethernet cable
    • Some Fair-Rite ferrite snap ons with multiple turns

I obtained a weatherproof enclosure and some pex tubing and specialty cable glands and built an antenna housing. Inside the enclosure I mounted the amplifier, adding a large gauge copper wire for the antenna element, and used an affordable tri-shield RG11 with specialty connectors as the feedline for the antenna.

The antenna measures approximately a 2 meter diameter, and is mounted about 5 feet off the ground at the base of the antenna. It is located outside of a remote shed at the edge of my property, and the ethernet (alternatively, wireless repeating parabolic dish with router) mirrors the USB data back to the PC in my basement which serves as the shortwave receiving server host.

I have been overwhelmed both with the amount of new noise and new signal that this antenna picks up.

In shortwave, the other night, I was picking up stations around the world.

Tonight, I was able to very clearly make out CHLO. I am located in EM38, over 700 miles from the transmitter, which only operates at 250 watts during the night time.
I was also able to pick up some international NOAA NAVTEX alerts on 518kHz about a right whale slow zone in the Atlantic off the shore of New Jersey.

I would  highly recommend this antenna amplifier.

Yours sincerely,

Joshuah

Thank you so much, Joshuah, for allowing me to post your note here in the SWLing Post. I’m so glad you found such an affordable way to cobble together an effective antenna system to not only mitigate interference, but also afford you DX-worthy reception. 

I’ve only heard good comments about Cross Country Wireless as well. 

Again, thank you for sharing your impressions and details about your setup!

Click here to check out the Cross Country Wireless amplifier.

Guest Post: Pavel’s Homebrew “Monster” Drain Pipe FSL Antenna


Many thanks to SWLing Post contributor, Pavel Kraus, for the following guest post:


Building a Drain Pipe FSL Antenna

by Pavel Kraus

Hi, I greet all DX fans and the entire SWLing Post community! I enjoy reading reading this blog and the diversity of contributions from our authors and contributors; many thanks from me for so much useful information.

The following are the construction notes of my FSL antenna, which I designed thanks to the suggestions of GaryDeBock, and other FSL designers.

The antenna is a classic design featuring 60 ferrite rods 200x 10 mm, which are placed on a plastic sewage pipe.

Pict 3: Pipe with ferrite rods and windings

Pict 4: Pipe with ferrite rods and windings

In addition, sewer pipe sections are used for the entire antenna cover. I assume that this material can be obtained in other countries as well. Continue reading

Jock explores “The Essential Listening Post”

Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:


The Essential Listening Post

By Jock Elliott, KB2GOM

Listening to shortwave radio (or any radio, for that matter) is just plain fun.

So what do you need to get in on the fun?

A radio. With today’s crop of portable SW radios, many of which have search and store capabilities, a newbie SWL can get started quickly without a lot fuss and bother and no extra stuff. Just hit the search and store function (it has different names on different radios), let the search function do its thing, and step through the memories to see what’s out there. If your radio doesn’t have search and store, you can just tune around to see what’s currently broadcasting or, if you have a computer or smart phone, use it to explore one of the online directories like https://shortwaveschedule.com/

What follow next are some things that I’ve found increase my enjoyment of SWLing. Continue reading

GRAHN Spezialantennen currently closed

Many thanks to SWLing Post contributor, Dan Robinson, who notes that Grahn Spezialantennen is currently closed due to the fact that Mr. Grahn is undergoing extended medical treatment.

Dan received this message from Christine Grahn who did not indicate if/when the business might re-open. We certainly wish him all of the best in recovery.

Click here to view the Grahn Spezialantennen website.

Grayhat’s NCPL (Noise-Cancelling Passive Loop) antenna “tweak”

My NCPL antenna

Many thanks to SWLing Post contributor, Grayhat, who shares the following modification he made to a Noise-Cancelling Passive Loop antenna last year. He’s kindly allowed me to share his notes here, but apologized that at the time, he didn’t take photos of the project along the way and recycled many of the components into yet another antenna experiment.

Grayhat writes:

Here’s a simple tweak to the NCPL, made easy for anyone. Let’s start with the commercial NooElec 9:1 balun version 1 (not 2) … made in USA.

Look at the schematic of the balun:

Cut the R1 (0 Ohm resistor – jumper) so that the center tap of the transformer won’t be connected to ground, then solder a short piece of wire to the tap.

The first pic (top) shows the balun seen from top side, the arrow indicates the small hole going to the transformer tap.

This pic shows the bottom of the board with the trace to cut and the spot for soldering the tap wire (needs cleaning with a bit of sandpaper to remove the cover paint). The solder is as easy as 1-2-3 once the trace is cut and the spot cleaned just insert a wire from the top of the board and solder it to the bottom and there you go!

Build the NCPL using “fat” coax (RG8 will do) with the top cross connection.

NCPL modification schematic

Side note: the top “cross connection” is the weak point, so it would be a good idea putting a short piece of (say) PVC pipe over that point, the piece will also help suspending the loop or sticking its top to the support pole, as for the feedpoint, a small electrical junction box will fit and protect the tiny balun from bad weather

Now the difference: connect the two center conductors of the NCPL to the balun input and the braid to the wire going to the center tap (as above).

Such a configuration will give some advantages over the “standard” NCPL one. The loop will now be galvanically isolated from the feedline/receiver so it will have much less “static noise.” Due to the tap, the typical 8 pattern of the loop will be preserved, this means that the loop will now have much deeper nulls.

By the way, the balun could just be wound w/o buying it. I suggested the nooelec since that way anyone with little soldering ability will be able to put it together. Oh and by the way it’s then possible adding a small preamp at the balun output if one really wants, any preamp accepting a coax input will work. 🙂

Again, if you can/want, give it a try !

Many thanks for sharing this, Grayhat! We always welcome your inexpensive, innovative urban antenna projects!

Post readers: If you have question, feel free to comment and I’m sure Grayhat can help.