Rabbit ears for 2 meter?

[majoco]

A quarter-wave for each element (about 19") is the only one that you could possibly make out of bunny's ears as anything other than odd multiples of a quarter-wave won't give you a 75ohm impedance.Three-quarters would be OK for impedance but you won't get any better signal in or out.

 

[LtDoc]

What length for those 'ears'? A 1/2 wave center fed antenna is about 70 - 75 ohms if it's a 'straight' antenna. If you tilt those 'ears' just a bit, make the angle between them less than 180 degrees, the input impedance starts going down to closer to 50 ohms. So, if you have a meter, try that 'angle' thing to drop the SWR. There's no real benefit to using a full wave center fed doublet. First, the input impedance isn't going to be even close to 50 ohms. Then the radiation pattern isn't going to be a 'usable'/predictable as with a 1/2 wave. Wanna try it? Have at it, see what you think.
- 'Doc

 

[joseph2020]

Thank you for the replies. This antenna theory is kicking my butt. What is the eaiest and cheapest way to learn more about antennas and how they work. I know the basics, but even a simple project like this needs more than the basics, therefore the questions.

What about element thickness (question #2). Does it matter much in this situation? thanks again.

 

[LtDoc]

Element thickness may make a very slight difference in the final length, but not much, and I seriously doubt if you'd ever need worry about it.
- 'Doc

 

[joseph2020]

OK, thanks!

 

[smokeybehr]

The recommendation to make a J-pole out of twin-lead is about the best idea. I've made several of them for 2M and 220mhz. You can also make one for 440, but the tolerances are a LOT tighter, and it's easier to make one of those out of brazing rod or 10-12ga solid copper stripped out of Romex.

If you have pipe soldering skills, then you can take a try at a "Copper Cactus" which is a J-pole made out of copper water pipe for 2M. I made a J-pole out of brass tubing for 440, and it works spectacularly.

 

[joseph2020]

smokeybehr, thanks for your informative reply. I wanted to build the "ears" antenna because it was cheap (very important right now), and Ithought it would be a "fun" and easy project, besides, I love using old technology.

I also just built a twin lead J pole from these plans: The Twinlead J-Pole Antenna. I had my friend do the soldering (she is a professional) and should be picking that up and doing some field testing some time this weekend.

If it works, I might try the 10 or 12 ga stripped romex next. Do you think that would be worthwhile improvement from the twin lead J? Thanks again.

 

[LtDoc]

I seriously doubt if there will be any noticeable difference between a 'J'-pole mad of 10 - 12 gauge wire and one made form 'twin-lead', or one made from copper pipe. At least, not from the size of the conductors.
- 'Doc

 

[joseph2020]

Thanks again Doc.

Any other opinions are always welcome welcome.

 

[joseph2020]

sorry about 2nd welcome above...It had to be the keyboard fault.

Ok, the "cheapo antenna project" is almost done...the latest 2 meter test results are in:

The rubber ducky that came with the radio shows about 3 bars. the telescoping antenna ( 20 inches) about 4 bars, the "ears" antenna about 6 bars, and the twin lead end fed J pole about 8+ bars and the only one where I could hear simplex about 30 miles away (no repeater)... we got a winner.

Getting a SWR will be the next step, but I'm guessing it is lower than critical or the radio would shut down. ]F anyone knows of a cheap used working SWR for sale for VHF please PM me. I sure wish I could get my hands on some of those old ham radio magazines (1940s - 1960s) when everyone just homebrewed all their equipment.

Thanks to all who replied to this topic. I am open to any further thoughts/ideas.

 

[joseph2020]

I am famous thanks to the ears

I thought this was very funny. Try this, google or yahoo search for "rabbit ears for 2 meter" or just go here rabbit ears for 2 meter - Google Search Does that mean I am now famous? Or did I just show the extent of my ignorance internet wide? :lol:

 

[lbfd09]

I thought this was very funny. Try this, google or yahoo search for "rabbit ears for 2 meter" or just go here rabbit ears for 2 meter - Google Search Does that mean I am now famous? Or did I just show the extent of my ignorance internet wide? :lol:

Yep - you are not immortally embraced in Internet History.

Congrats. On both asking the question and helping all of us learn here.

 

[majoco]

Join your local radio club and after they find that your'e 'acceptable', somebody will give you an SWR meter! I have three kicking around here!

 

[joseph2020]

question answered

Thanks for your replies guys!