Indoor Antennas Worthy Of 007

Many ham radio operators now live where installing an outdoor antenna is all but impossible. It seems that homeowner’s associations are on the lookout for the non-conformity of the dreaded ham radio antenna. [Peter] can sympathize, and has a solution based on lessons of spycraft from the cold war.

[Peter] points out that spies like the [Krogers] needed to report British Navy secrets like the plans for a nuclear boomer sub to Russia but didn’t want to attract the attention of their neighbors. In this case, the transmitter itself was so well-hidden that it took MI5 nine days to find the first of them. Clearly, then, there wasn’t a giant antenna on the roof. If there had been, the authorities could simply follow the feedline to find the radio. A concealed spy antenna might be just the ticket for a deed-restricted ham radio station.

The antenna the [Kroger’s] used was a 22-meter wire in the attic of their home. Keep in mind, the old tube transmitters were less finicky about SWR and by adjusting the loading circuits, you could transmit into almost anything. Paradoxically, older houses work better with indoor antennas because they lack things like solar cell panels, radiant barriers, and metallic insulation.

Like many people, [Peter] likes loop antennas for indoor use. He also shows other types of indoor antennas. They probably won’t do as much good as a proper outdoor antenna, but you can make quite a few contacts with some skill, some luck, and good propagation. [Peter] has some period spy radios, which are always interesting to see. By today’s standards, they aren’t especially small, but for their day they are positively tiny. Video after the break.

If you think spy radios were small then, you should see what you can do now. Then again, some of the most famous cold war spy radios didn’t have any obvious antenna or even required power.

21 thoughts on “Indoor Antennas Worthy Of 007

  1. Loop antennas are great, and many hams have installed loop antennas around the outside edge of their roof (since many homes have radiant barriers lining the inside of their roof).

    One issue with loop antennas is that you don’t want your noise sources (appliances, plasma TVs, noisy wall-warts, etc) inside the loop. Many hams have run loops around their back yard, for quieter reception.

    You’ll either want to feed your loop with ladder line and place an appropriate tuner near the radio, or place an auto tuner/coupler at the loop feed point and run coax to the radio.

  2. Canada a few years back forbade restriction of washing lines, clothes lines, for reasons of energy efficiency. So if you set up horizontal wires only up to 10ft off the ground, that will cover you… but you’d want to use some clothes line hardware and make them strong enough to hang a few towels on occasionally to support the deception. Also you might get away with disguising a turnstile as a rotary clothes drier if you string it with a web of non conductive cord. Again, can’t mount very high to get away with that.

    In the US there’s always been the FCC protection of TV antennas, so bands that come close to those and use them directly or slightly resized “replicas”, or you can size as 1/8 wave or something to have a better than nothing antenna.

      1. When I was (much) younger I made a 2m slim jim that was thin enough to go up the inside of a TV aerial pole, I pushed it up there with a bit of bamboo and it has a small tang that sprang out at the top to retain it. Nice height, and discreet.

  3. I would ask the homeowners association who most of them are drunk with power to look at the otard law otard it is a federal law that come into effect 2001 in regards to TV antennas and such

  4. “Paradoxically, older houses work better with indoor antennas because they lack things like solar cell panels, radiant barriers, and metallic insulation.”

    What about brick or cement?

    1. Brick of cement contains steel reinforcing bars or mesh. Plaster and stucco also may have reinforcing mesh. Walls have wire, conduit and plumbing. There are generally rain gutters around the edge of the roof. All of this stuff can complicate antenna performance. Under the roof but as far from the rest of the house structure as possible is probably the best choice for an indoor antenna location. Gutters can be used. Balconies can hide a loop. You can throw a random wire out a window. There are a virtually unlimited number of ways to contrive some sort of antenna. Any antenna is better than no antenna.

      1. Metal slinkies (Stairwalker spring type things) are harder to find these days, but I’ve seen those recommended as “throw out the window” long wire verticals for 2nd floor up dwellers. Weight on the end to pull them out.

          1. In the farm store thay have gates for electric fence that look like small slinky
            About 1 1/2 around n about 5 inches long but stretch out over 16 feet
            Thare made to b out side mabe thay will last longer longer thay come 2 to a pack
            Thay look like antenna to me so I got some see whut I can come up with
            73 n9prf Joe

  5. Fine Business article. Lots of room outside for me here in rural Western Kansas. I use a vertical and an end fed Zepp but recently fried the final on my KEN TS430S. Very unforgiving. Wish I still had my tube Drake 2NT as I only do QRP CW now. QSO me at

  6. On April 30th 1983 an illegal radio station belonging to “Solidarność” (Solidarity), a workers union opposing the communist government of Peoples’ Republic of Poland, started its first transmission. This station operated in the town of Świdnik, which is only 21km from my home city of Lublin. The transmitter, powered by 18 D-cell batteries in series, was cleverly hidden inside a tape recorder, the Unitra ZRK B113 “Kapral” model. The transmitter was found many times by the the secret police of communist Poland, but no one ever discovered its true function and purpose. As for antenna to transmit on 66,5MHz at 3W at first, and later at 6W, they used dipole made of normal wire, hung usually across the room, and they earthed the whole thing to the radiator. Because this radio started as a tape recorder, people operating it recorded their programs on tape and transmitted them that way. This also helped them perform few illicit transmission from a playground, powering the upgraded radio with car battery.

    The second radio was hidden in a french tape recorder and reached 62 Watts of power. This one was used on February 14th 1984 to hijack the audio band of 1st. Program of polish state television. There was a transmision of the funeral of the First Secretary of the Central Committee of the Communist Party of Soviet Union, Andropov. So just imagine the reactions of everyone in the region, where radio operated, when suddenly another member of Central Committee, Konstantin Chernenko, started talking in polish about state repressions of workers union in Poland, criticizing them. And the true speaker actually matched the voice to the Chernenko. The transmission was well-received in the town of Świdnik, despite the fact that the TV signal was transmitted from Lublin, 21km away. Turns out that weaker transmitter nearby will outperform the stronger one that is some distance away. Even with simple dipole hung across the living room in a flat…

    1. It seems obvious that “authorities were pretending to pay the police, and police were pretending to do their own job “.

      Any competent DF radio operator could have easily located the station by triangulation. And then, send in competent people to do search.

      Why they didn’t, is left as an exercise for the reader.

      1. They actually triangulated the locations of transmissions on few occasions. Usually to blocks of flats. So people were on lookout for the triangulation trucks and the police, so the operators had plenty of time to stop the transmission, remove the antenna and just hide the radio in plain sight.

        On one occasion one of the people had his flat searched, and tapes with previous transmissions were found, with the notes from the ringleader. The unlucky man was arrested, and the ringleader was followed for few months.

  7. Most interesting long wire antenna I saw was in an attic of a house that had been built & rebuilt starting pre-1776, 1806 and 1928. In the attic, and thumbtacked to the carved & pegged rafters was an orderly zigzag of enameled wire. Quite a contrast to a house w cedar shake siding and roof that had initially been built by shipbuilders.

  8. Sailors deal with the issue of less-than-optimal antennas pretty much all the time. The usual solution is a autotuned whip or backstay (after placing insulators in the wire). The good news is that with a proper ground, they work pretty well as the ground plane is vast!

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