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The Cyclops - Matching Transformers for Beverage / Longwire / Dipole / Random wire / K9AY / LoG Loop on Ground / Flag / EWE And Other Antennas

Just $29 with Free Shipping! (We Ship Within The USA Only)

This is what I've used for a while with my LoG (Loop on Ground) antenna, with great results. I've had others ask about buying one, so now here it is!

Available with 200, 300, and 450 ohm input impedances.

These matching transformers are encased in epoxy resin, making them extremely weather resistant. They measure about 4 by 1 by 1 inches and weigh approximately 3 ounces. There's an eyebolt for adding a support rope, which should be used only to hang the transformer. While epoxy resin is extremely hard, it is not designed for loads under tension. You need to use antenna insulators/etc to hang your antenna wires and take all of the weight/stress, otherwise the resin could fail.

Proper matching of your antenna is critical if you want the best possible performance. While small impedance differences do not cause significant problems for receiving antennas (unlike transmitting applications where the resulting high SWR is a problem), large differences can.

Your radio's antenna connector typically has a 50 ohm impedance, however the impedance of your antenna can be significantly different. This is especially true for Beverage, Random wire (Longwire), K9AY, Flag, Pennant, Ewe, and Folded dipole antennas which tend to have much higher impedances. Directly connecting these antennas to the 50 ohm coax running to your receiver results in a significant impedance mismatch, with high losses resulting in weaker signals. The antenna's pattern can also be affected. The net result - your antenna is not working as well as it should (and it could in fact be working very poorly).

This is solved by using a matching transformer, which allows maximum signal transfer between your antenna and receiver. Cyclops matching transformers are available with either 50 ohm UHF (SO-239) connectors, or 75 ohm F connectors (it's popular to use RG-6 TV style coax even at HF for receive applications as it is inexpensive, easy to find, and low loss).

Each coax connector style is available in three different transformer ratios, to match different antenna impedances. The wire colors are different for each nominal antenna impedance, for identification purposes:

Wire Color UHF Connector F Connector
White 450 ohms 450 ohms (443)
Yellow 200 ohms 200 ohms (190)
Black 300 ohms 300 ohms

It's not possible to get "perfect" impedance matches since you have an integer number of turns on the primary and secondary of the transformer, but these are more than close enough for any real world antenna.

Transformers are built to order, so please allow several days for shipment.

300 Ohm UHF Connector $29 - Free Shipping

200 Ohm UHF Connector $29 - Free Shipping

450 Ohm UHF Connector $29 - Free Shipping

200 Ohm F Connector $29 - Free Shipping

300 Ohm F Connector $29 - Free Shipping

450 Ohm F Connector $29 - Free Shipping

View the items in your cart, check out via PayPal. You do not need a PayPal account to order, you can use your credit card without an account.

Note: This transformer is for receive only applications, not for transmitting. Transmitting into it will damage it and possibly your radio. It does not provide protection from lightning. You should always use a lightning arrestor with any antenna, and follow the appropriate electrical wiring codes. Antennas should be disconnected during storms for maximum safety, and to prevent damage to the transformer, and your radio. All antennas must always be kept away from power lines, with no possibility of contact under any circumstances.

Questions? Send them to us at

Last updated February 4, 2019