as most of you know i am in a single story rancher style house that is 54' long and since it is a rental i dont want to have wires strung up all over the place. so today i noticed the G5RV jr antenna, it is 51' long and would fit just fine in the attic but i would have to figure out how to drop the ladder line into the house. i will be picking up a tuner next week so how do you guys think this thing would work connected to the rafters at the peak of the roof? it will only be 18' or so off the ground though. its hard to beat for the price if it will work, $30. ideas?

Do a search for W8AMZ and look at the G5RV's that he makes. It might fit your needs nicely. I have 2 one full size here at the QTH for 80/40 and of course anything else when I want to use something other than the yagi. Other is his 1/2 size and that rolls up REAL small and is my ARES/Field Day antenna. His stuff is just 1st Class all the way!!!
Sarge

I have one inside on my wall of the room, I had to shorten mine with coils. It works fine, but worked better when full size. I used it to make several contacts in the Ukraine and Russia.

Use 14 ga stranded insulated THHN wire.  Wind the coils the specified numnber of turns such that the turns are touching, and due to the thickness of the insulation the coils will come out 9 turns per inch.  That takes one variable of construction out of the equation.

Use 10 ferrite beads, Fair Rite RCT-2, which can be purchased at HamCity.com, Palomar Engineers, and others.  If you can't find these, IM me for sources.

OR replace the center insulator AND the ferrite beads with a 1:1 CURRENT balun such as http://www.universal-radio.com/catalog/antsup/2452.html

Overall length is 48'.  Don't let the ends touch or be close to anything other than an insulator.

With a tuner works 75, 40, 20, 17, 15, and might tune on more.

I had good luck with my G5RV Jr. I ran that antenna on everything from 10 through 40 (with one exception, but I don't remember what it was now. Maybe 15? 12?) and I have no complaints. I even managed ot make a few contacts on 80 with it, but I wouldn't recommend it.

Overall, it's a great antenna for those who don't have a ton of room.

i know, i know, but for the price of just the center feed balum or even the ferrite beads i can buy the G5RV. now, i wont have 80m but it seems to me for the price the G5RV is a better choice. do you have the original link to that antenna? i cant seem to find it but i know i have seen it before on one of the antenna sites.

That one is mine.  I AM the original source.



73,
AFM

OH,

HankEllis has one of these in his attic.

Like any attic antenna, it ain't great, but it's better than nothing.  

I may have to support Acadiana by buying locally, LOL Just saw a sign that said that..

A G5RV is not the best but it is cheap to build one.  I used one for portable and base operations for 15 years.  120 countries barefoot with one.   It finally was destroyed in one of the Valleys summer zephyrs.   Now using a 90' folded dipole and may upgrade to a tilted, terminated folded dipole for lower noise and to get on 160 m easier.

Additional sketches on the attic antenna installation above.


Top View:




Side and End Views:

I've been using AFMs designs for the lower bands in my attic since day one. They work. Yeah, you need a tuner but the tuner built in my rig handles it fine.

For the upper bands I have fan dipoles. 20/17 on one and 15/12/10 on the other. 6m loop from M2. 2m J-pole for packet (soon to be repurposed to APRS WX station). 2m Elk LP for 2m simplex and SSB.

As soon as it cools off I'll be spending some time in the attic. Mount a second Elk LP so I have both polarazations. Put both of those on a rotor. Remount the 6m ant to a better location. Finally build a new 30/40/80 utilizing the extra space I found up there. Install some chokes on the ceiling speakers of the home theater so the XYL can quit complaining of hearing the CW.

(AFM. Expect an email soon on the new lower band project.)

Cool!

Hank, what did you get for SWR on each band, 75, 40, 20, 17, 15 meters, and did 10 meters work out?

AFM

If you run the G5RV you could drill a hole in the header panel of the wall near the radio. You would drop the ladder line into the wall.

If it were me though I'd build a OCF dipole.

way longer than i have room for. the plan is to run the ladder line from the G5RV down through the closet in the living room.

AFM, any ideas on the SWR readings on this design? i have the PVC and will be picking up the wire tomorrow. going to build the center feed balun as well. i have an antenna analyzer but wanted some idea on what it should run and how to adjust it.

I built a couple of these for some other guys, and i was getting 1.2 - 1.4 on the upper bands, and 1.4-1.5 in the target region of the 75 m band, around 3.900 mHz.  Of course, tuning may change in an attic due to wiring, piping, duct work, whereas I tweeked these antennas in my yard.




Segments A and B are 20 meters.  

Segments C and D are 15 meters.

Segments E (along with red coil and segment A) and F(along with blue coil and segment B) is 75 meters.

Segments G (along with brown coil and segment C) and H (along with green coil and segment D) is 40 meters.

If resonance is where it should be, for example, 20 meters at 14.200 mhz, but SWR is too high, try adjusting the offset by winding one turn more onto the inside of the red coil, and taking a turn off the inside of the blue coil.  That will maintain the length, but shift the feedpoint.  If SWR is worse, go the other way with it.

Ditto 15 meters.  

Fine tuning 75 and 40 meters, if resonance is where you want it, but SWR too high, try taking off a turn from the outside of the coils on one side, add a turn on the outside of the coil on the opposite side, keeping the same overall length.