Many thanks to SWLing Post contributor, Dave Zantow (N9EWO), who notes:

Here is an interesting looking indoor passive HF loop antenna [photo above] that Randy McIntosh just started selling in the US. Made in Greece. Model TLA500C. Sorry it’s not for MW.

Here’ are the specifications/description from the eBay page:

This sale is for an HF magnetic loop antenna that should be attractive to anyone living in an apartment, residence, or other location where it is not possible to erect an outside dipole antenna. If you can erect an outside antenna, this is always the best solution for reception as no inside antenna can compete with a good outside antenna for the very best signal reception. But erecting an outside antenna is not always possible for many people desiring to listen to amateur radio or shortwave signals. Thus, this antenna offers a solution to such hobbyists handicapped by personal physical limitations to mount an outside antenna, minimal yard space to erect such an antenna, apartment living, or HOA restrictions.

This antenna spans a tuning range spanning 3.5 MHz through 40 MHz and thus covers 80 – 10 meters on the amateur radio bands, all international shortwave bands plus the 11 meter CB bands. The antenna comes with a 3′ coaxial cable to attach the antenna BNC output to a SO-259/PL-259 input of your receiver (most receivers).

Simple assembly directions are also included and you may be view this information in the last picture at the top of this listing. If you have a different input on your receiver other than the PL-259, you will need to acquire the proper interconnect cable from another Ebay seller. Assembly takes 5-10 minutes using only a proper sized Phillips head screwdriver and the antenna can be disassembled to transport to a remote DX location or for convenience in your travel luggage…..or as our picture shows, located permanently at your home listening room or bedside. Depending upon your preference and the dimensions of your receiver, the antenna can be set on top of or next to your receiver (see pictures at the top of this listing) during operation. Please remember that this is a “receive only” antenna and cannot be used to transmit signals.

Features:

• non amplified….no batteries required
• works on wide variety of communications receivers both stationary or portable
• light weight aluminum construction weighs about 1 lb with the interconnect cable
• portable – can be disassembled and folded into a low stature for compact transport
• sharp tuning helps filter strong non-desired out-of-band signals
• low noise loop design helps filter RF noise often found inside a home or apartment from lighting or appliances
• tuning range of 3.5 MHz – 40 MHz
• small loop antenna assembles to 18″ diameter at the broadest point
• great alternative for signal reception when an outside antenna is not possible
• very easy set up and connection

Thanks for the tip, Dave! This looks like a practical design for portable and low-profile operation.

Since it is passive antenna design, I image you would have to re-tune the antenna for peak performance each time you shift frequencies. It looks like the control panel would make this a pretty simple process.

Click here to view this antenna on eBay (partner link).

Post readers: If anyone has used this antenna, please comment with your impressions or contact me with your review.