Using a TV Dipole Antenna for NOAA Satellite Reception
Over on YouTube icholakov has uploaded a video showing how effective a simple old TV bunny ears antenna can be at receiving NOAA satellite images. The old TV antenna is telescoping so it can be adjusted to be resonant for many frequencies, and for NOAA satellites about 20 inches makes it resonant. Using the antenna as a V-Dipole and placing it in a North to South direction optimizes the radiation pattern towards the sky, allowing for good reception of the NOAA satellite. Using it this way also helps to null out strong vertically polarized stations. More information on the V-Dipole can be found on our previous post where we posted about Adam 9A4QV’s idea to use the V-Dipole for satellite reception.
Also related to this post is a sneak preview on our new product: We’ve also caught onto the idea that TV antenna dipoles are extremely versatile, and are in the final stages of releasing a simple telescopic dipole product similar to the TV antenna used in this video. It will be released as an antenna set that comes with some portable mounting solutions like a suction cup and bendy tripod, and 3M of RG174 coax so that the antenna can be used anywhere. Target price is $10 -15 USD incl. shipping from China. This will probably also replace the stock telescopic whip antenna currently used in our dongle sets since the telescopic dipole is simply much more versatile.
remember when using the rabbit ears make sure that your RHCP AND LHCP are correct,or these antennas will not work correct de KB5ZCS…….
Thank you for the comments. Thomas did not use any balun matching as the signal seemed to be strong enough.
I have purchased this rabbit antenna to use it as a portable dipole (it’s about $3 on Ali) after removing the round metal part.
In this picture you see the connections inside.
As you can see the round metal part is not a decorative part or a reflector but is a hairpin match.
Considering that each telescopic element is 0.20 to 0.60 meters long the resonance as a dipole is between 120 and 370 Mhz only but it is intended to use for tv frequencies up to 800Mhz. Why the airpin match? is there a logic behind antenna dimensions, hairping match and frequency bands that it is supposed to cover?
I did not have the time to think about it yet but for the moment i do not need another portable dipole so it is more usefull as a brainstorming tool.
Just a hint regarding the rabbit ears. There should be a 1:4 transformer inside the plastic base holder where the 75 ohms (or so) is transformed to 300 ohms twin lead impedance. Connecting there 75 ohms or 50 ohms coaxial cable will create mismatch and extra losses. Advice: open the “black magic box” and remove the 1:4 transformer and connect the coaxial cable directly to “ears”. Do not throw the transformer, it may be handy for some other projects like closed 200 ohms dipole antenna.
Most of the rabbit ears like the one in the video with twin lead that i’ve seen don’t even come with a transformer in the base. They’re just connected up directly.
Sorry for late reply:) actually my antenna from old tv(manufactured probably 40 years ago) has inside 1:1 balun similar to this http://vk6ysf.com/balun_1-1.htm
(I suppose it’s better not to remove it). Anyway it’s recommended to disassemble antenna and inspect what is inside and than decide whether any improvement is reqired.
As for performance it works almost same as home build coax qfh, as Adam mentioned in his blog. SNR is 2-3 dB less for high elevation pass but when pass is near the horizon the difference is more noticeable.