Saturday, July 9, 2016

TTFD antenna

The TTFD was developed by the navy during WWII.
It seems "Buck" Rodgers developed it in 1958. His version with info can be found here.

EDIT: the link broke. A search for TTFD will take you to some good info. The diagram above with the formulas is basically all you need to build one. It has been made under several names. A search for FLAG antenna will find some good info also. The main difference between a TTFD and a FLAG is the way they are mounted.

BROKE LINK...........

Another option for the apartment dweller?

Tuesday, July 5, 2016

My sidewise flag. It's the noise factor that sold me.

My antenna is a sideways flag. I have a 1.2KOhm resistor between the two blue dots. The antenna transformer is 20T:9T on a 1/2" yellow toroid. We have a low power local (about 50 miles) that I couldn't receive in the house or shop. I could receiver it on the car radio with noise and it would be swallowed up by the noise as I travel around town. With this antenna I am receiving it. It is a little noisy but steady. I have also been listening to the ham net roll call on 80M and 40M. I'm listening to ABC Australia as I write this. It is a design worth trying because of the RFI improvements. With a simple wire antenna I have much to high a noise level.