I thought the members of this forum would like to see a tuner I built to take advantage of the longwave capabilities of my receiver.
I'm using this tuner with a Yaesu FRG-100. The tuner interfaces with an 11 meter band coaxial vertical dipole. The tuner operates as a Hi-Q series resonant circuit. With the vertical dipole, I can pretty much hear any signal available that makes it through the noise level. This past November, I was hearing the European LW broadcasters making the trip here into the midwest. Other signals such as the 500khz amateur radio experimenters are also heard quite easily. Of course there are hundreds of navagational beacons on the band to be logged.
Notice the small switches on the tuning capacitor that change the tuning range. I found that nice Hi-Q coil in a scrapped radio, and knew it would be perfect for this project. You may notice the small coil and trimmer cap at the antenna input. That is a resonant circuit to "kill" the signal of a local 50KW pest on 560Khz. There tends to be some intermod on the LW band without this "trap". The coiled output with the ferrite ring couples to the Yaesu. I have replaced this coil since the picture was taken with a lowpass filter that cuts off at the bottom of the BCB to further reduce the chances of intermod.
The tuning range of the tuner is roughly 560khz at the high end, to about 150khz at the low end. I can lower the tuner range very easily to about 100khz by inserting a 4" ferrite rod into the coil tube.
I'm using this tuner with a Yaesu FRG-100. The tuner interfaces with an 11 meter band coaxial vertical dipole. The tuner operates as a Hi-Q series resonant circuit. With the vertical dipole, I can pretty much hear any signal available that makes it through the noise level. This past November, I was hearing the European LW broadcasters making the trip here into the midwest. Other signals such as the 500khz amateur radio experimenters are also heard quite easily. Of course there are hundreds of navagational beacons on the band to be logged.
Notice the small switches on the tuning capacitor that change the tuning range. I found that nice Hi-Q coil in a scrapped radio, and knew it would be perfect for this project. You may notice the small coil and trimmer cap at the antenna input. That is a resonant circuit to "kill" the signal of a local 50KW pest on 560Khz. There tends to be some intermod on the LW band without this "trap". The coiled output with the ferrite ring couples to the Yaesu. I have replaced this coil since the picture was taken with a lowpass filter that cuts off at the bottom of the BCB to further reduce the chances of intermod.
The tuning range of the tuner is roughly 560khz at the high end, to about 150khz at the low end. I can lower the tuner range very easily to about 100khz by inserting a 4" ferrite rod into the coil tube.
