Category Archives: How To

How to safely archive QSLs, postcards, photos, and printed memorabilia

Recently, an SWLing Post reader asked this simple question:

“If you were me, would you laminate [a super-rare] QSL card?”

The short answer–?  Please don’t!

Never laminate a QSL card, photo, page or postcard

You should never apply heat-seal or adhesive (cold) seal lamination to a QSL card or any other paper memorabilia if your ultimate goal is to protect and archive it.

Why?  Doesn’t lamination, for example, make your card impervious to moisture (and spilled coffee)?  Sort of.  So that makes it safe for the long term, doesn’t it? Well…not exactly.

These forms of lamination, over time, basically destroy printed media. In the short term, laminating your cards can look great, and will keep some of the coffee off (though it may still seep in the sides); in the long term, however, the (petroleum-based) plastic can “off gas,” causing a detrimental chemical reaction with the media it attempts to protect.  Plastic can also be acidic.  Coupled with the lamination heat (or the adhesive, in the case of cold-seal lamination) these processes can actually speed up the aging process “causing progressive deterioration and eventual embrittlement,” according to one archiving source.

I feel fairly passionate about this because, during my undergraduate studies, I worked for my university archives department where I was taught (by an excellent and knowledgeable archivist) to handle, document, index, and preserve sensitive documents, books, photos, cards, slides and other forms of media (known in the trade as “ephemera”).  Many times, we’d receive important documents or photos from donors who had laminated them, believing they were archiving these items for future generations. Alas, we saw the results of the lamination damage first-hand:  decades-old items that had been heat-laminated were separating and clouding up, often tearing apart the item inside. Our head archivist likened laminating to a self-destruct mechanism.

Take away? Lamination is a very bad idea for the long-term protection of any print media.

How to archive a QSL card––or any document, for that matter

Archival sleeves come in all forms. This one holds four cards and fits in a three ring binder.

Fortunately, there are effective (and fairly affordable) ways to properly archive and organize your QSL card collection, as well as other sentimental and/or valuable ephemera.

Look for archival transparent sleeves supplied to libraries. These are generally made of polyethylene, mylar/polyester, or another transparent archival material that passes the Photographic Activity Test (PAT).

In short: If you find an archival sleeve, from a reputable seller that passes the P.A.T. test, you’ll know it’s safe.

Archival products are acid-free, lignan-free, and chemical softener-free, thus should not interact or bind with the media you’re preserving as non-acid-free items are prone to do. With anything I wish to archive, I go with archival quality all the way.

For example, I make sure not only the clear sleeves or pages are archival, but that the binder or box containing the items are acid-free and of archival quality, as well. Any labels I use are archival, as well . That may seem like overkill to many, but it’s just what an archivist would do!

Storage of the media is also important; you don’t want to put your cards in archival sleeves and then leave them in a damp shed or shack where moisture can become trapped between your card and the encapsulating archival sleeve; mold could still develop.  So a dry, somewhat temperature-controlled environment is key.  Generally speaking, keeping ephemera indoors where you live may be a better option.

Sources of Archival Materials

A simple acid-free box can store hundreds of QSL cards in archival sleeves sleeves.

Archival products are more expensive than standard office products, but they’re worth it. Make sure you’re purchasing the best quality you can afford. Two of my favorite suppliers are Gaylord Archival and Light Impressions, though there are many other reputable ones out there.

Amazon and eBay offer sources of archival quality products, as well, and pricing can be more competitive than either of the retailers I’ve listed above.

As for myself,  I only buy archival products from retailers that specialize in them. Both Light Impressions and Gaylord Archival have helpful staff you can call on the phone. They’ll help you find the best material for the preservation of your collection of QSL cards or whatever else you may want to protect.

I’d rather support Light Impressions with my purchase knowing that their standards are strict and their reputation rides on their products meeting strict archival standards. If you’re going to pay for something to protect your memorabilia, I say, go for quality!

And in the meantime…give the heat lamination a miss.

Good luck with your long-term archiving!  And don’t forget to share those rare QSL cards with us here.

Video: Lightbulb vs Radio Beacon by Thomas Cholakov (N1SPY)

Many thanks to SWLing Post contributor, Ivan Cholakov (NO2CW), who writes:

My 11 year old son Tommy (N1SPY) completed a project where he compared a 1W lightbulb to a .25 W radio beacon that he put together and bet that the radio beacon can be heard around the world. I asked him to document his activities as he went along. The project took a couple of months but is now complete and we stitched together a video of his activities.

Click here to view on YouTube.

Wow–Tommy, you’ve done an amazing job here!

I especially like how you’ve taken time to explain the principles behind the various steps of the process. Brilliant job!

Tommy, your future videos are always welcome here. Keep up the good work and we’d love to hear how many new countries you’ve racked up on your WSPR system!

How to build a Milk Crate AM Broadcast Loop Antenna

Many thanks to SWLing Post contributor, James Townley, who shares the following guest post originally posted on his Shortwave/Medium Wave blog:


540 kHz to 1700 kHz Loop Antenna (Click to enlarge)

AM Broadcast Loop Antenna

by James Townley

Several years ago, I became interested in medium wave DXing. One of my limitations was the size of my yard, so I developed an interest in tuned loop antennas to compensate, because setting up a beverage antenna was out of the question. I experimented with different sizes of loops, and found that the bigger the aperture, the more gain the loop would have. The tuned loop antenna is also very directional, which allows you to reject, or null out interference from either noise or other stations. Loops are considered bi-directional in that they receive to the front and back, but not to the sides. The tuned loop antenna quickly became my weapon of choice for medium wave DXing.

Recently when the weather began allowing me to enjoy the outdoors, I decided to make another smaller loop antenna from a plastic milk crate I had lying around. I saw the idea on the internet when I observed that someone had used a milk crate for their loop. Click here to see a variety of tuned loop antennas that others have made. Whichever material you decide to make your loop antenna from, just make sure that it is not a conductive material. Wood, plastic, and cardboard seem to be popular materials for loop making. In the photo above, I am using my Sony ICF-2010 to listen to WCCO on 830 kHz. This station is nearly 200 miles south of me, but I am able to receive it with 9 LEDs lit on my signal strength meter while using the loop. There is no direct connection of the loop to the radio, it is inductively coupling with the radio’s own ferrite rod antenna.

If you are interested in making a loop antenna like mine, here are the materials you will need:
120 ft of 18ga insulated wire (I bought a 100 ft spool of cheap speaker wire and pulled the 2 conductors apart):

1 – Plastic milk crate
1 – 15 to 365 pF air variable capacitor (found in many old radios, or a google search to buy one from an internet store)
1 – Tuning knob. Any knob will do as long as it fits the shaft on the variable capacitor.
1 – Tape or wire ties. I used tape to secure the wire while winding, then hot glue when finished.

When you begin to wind your coil, use tape or a wire tie to secure the wire, and leave about a foot of wire. This extra foot of wire will later be soldered to the frame on the capacitor. As you wind your coil, pull the wire snugly and with each turn leave about a quarter inch spacing between each turn. The spacing isn’t critical as long as the spacing is consistent.  I wound 21 turns on my crate. This may differ for you, depending on the size of your crate, or the value of you capacitor. If you find that the bottom frequency isn’t low enough, you can add more wire to make a few more turns. This will lower the bottom frequency for you.

After winding the coil, you can solder each end of the coil to your capacitor. The beginning of the loop gets soldered to the frame of the capacitor, and the other end of the coil to the rotor solder lug on the side of the capacitor. If you do not have a soldering iron, you can use alligator clips to connect your loop coil to the capacitor as well. I secured my capacitor to the inside corner of the crate with hot glue. I put a generous amount of the hot glue onto the bottom of the capacitor frame, and held it to the crate until the glue cooled enough for the capacitor to stay on it’s own. I used enough to get the job done, but not so much that it interfered with the plates in my capacitor. The hot glue seemed to adhere very well. I then checked the spacing of my coil turns, and secured them with the hot glue as well.

I was very impressed with the results after spending some time with the loop. It’s small enough to maneuver around easily, but big enough to give it some gain, so I can listen to daytime DX. I may make another tuned loop using two crates to see how much more gain I get with the larger aperture.

Happy DXing,
James Townley


Many thanks, James, for sharing your project with us! This loop appears to be relatively simple and accessible even to those with little knowledge of soldering or homebrewing. I’m now wondering how a loop made of four milk crates might perform!

Click here to view James’ Shortwave/Medium Wave blog.

The SDRplay RSP2 on Linux: a step-by-step guide

The SDRplay RSP2

Many thanks to Jon Hudson with SDRplay who recently shared the following video by Kevin Loughin which details the installation and operation of of the RSP2 on Linux. Kevin has written scripts that make the installation process more accessible to those not as familiar with Linux.

According to Kevin, this will run on Ubuntu 16.04 and other Debian-based Linux distributions.

Check out Kevin’s video below (or on YouTube). Kevin also published a step-by-step guide on his blog.

Click here to view on YouTube.

Click here to read step-by-step instructions on Kevin’s blog.

Video: EB3DYW’s Homebrewed regenerative receiver

While browsing a videos on YouTube, I stumbled across this demonstration of a brilliant little homebrewed regen receiver by Javier Guillaumet (EB3DYW):

Click here to view on YouTube.

What a beautiful little receiver!

Though I’ve build a number of receiver kits, I’ve never built one from scratch. Someday, I will muster up the courage and do so, though!

If you like home-grow regen receivers, you must check out Dave Richards’s Sproutie II regen receiver as well. A true work of art!

Post readers: Do you have any homebrew projects to share? Please comment!