There's a dipole in my bedroom!

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I don't know why I did but I bought the MFJ-1778 G5RV 80-10 meter dipole antenna, knowing that I won't be able to install it outside my 3rd floor apartment. So it's going to be in my room, with parasitic conductors and all. I've read that I don't have to worry about the ends as much as the side of the poles that connect to the feedline (32ft 450Ohm ladder-line) and can fold or bend them to conserve space. My questions are as follows:

1) Would it be better to tape it to the wall or to the ceiling (or a combination of both)? The dimensions of the biggest wall in my room is about 15ft wide x 10ft tall.

2) Do I still have to worry about lightning since I'm inside? If so, grounding it would be very hard. Would sticking some wire into the third prong of an outlet suffice?

3) Since I have 32ft of ladder-line, my guess is curling it to save space would affect its characteristic impedance. Is this okay as long as the antenna tuner can account for the differences? Also, since I have 32ft, I'm not going to connect any coax to it...just feed it right to the tuner, yes or no?
 
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What are you trying to do with the Antenna? Receive only; transmit & receive, if so which frequencies or bands.
 
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Initially, just for reception, but I will eventually try to transmit only after I know I have everything right. I've had my General ticket for a while and haven't transmitted once (on VHF, UHF, or HF).

As far as which HF band...no clue...just wanna see what's out there. That's why this multi-band dipole was attractive.
 
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Does your antenna tuner have a balanced output connection or only coax (PL-259). If it does my suggestion would be carefully rollup the G5RV and place it the closet for the day you can put it up outside. Get some 300 ohm TV twinlead, some general purpose hookup wire. measure from about 2 feet off the floor over the ceiling to the same distance on the opposite wall. Cut the wire to fit add a piece of wood or plastic as a center insulator, install in the form of a U centered in the ceiling. Connect the twin lead from the center to your tuner and enjoy. Your biggest problem will be RF noise from TV's, computers just about anything electronic. Depending on your tuner you should achieve a good match on 40 thru 10; 80 may be iffy for transmitting. For receive it will work on all bands.

A lot of the fun in ham radio is expermenting with various antenna configurations, some work some not so good. Good luck!
 

SCPD

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G5RV's

wannabescannist said:
Initially, just for reception, but I will eventually try to transmit only after I know I have everything right. I've had my General ticket for a while and haven't transmitted once (on VHF, UHF, or HF).

As far as which HF band...no clue...just wanna see what's out there. That's why this multi-band dipole was attractive.

You are supposed to have the ladder line portion of a G5RV as straight as possible, at a right angle to the dipole portion of it. Having said that, I know someone who used to have a G5RV junior (10-40) io in their attic and have told me they had the ladder line portion "wadded" up and worked all over North and South Amercia, and into Europe. I have made European contacts with 10 meter verticals on the ground in the back yard, so just about any antenna will get you some contacts. . I know someone in Michigan who has got an end-fed metal Slinky strung up between his house and garage, and has worked the east and west coast. Bottom line, see what plays
 
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rf, I currently don't have a tuner, that was going to be another device I was going to buy soon. Matter fact I don't have a power supply either, but it's on the way (shipping from China takes a while....don't laugh). The transceiver (ic718) just has an unbalanced connector (so-239). Sounds to me like you want me to make my own dipole....and you know what....I think I'll give it a shot! Your explanation seems simple enough. I also haven't been much of an experimentalist because I don't feel I have enough theory under my belt yet. I didn't want to just go through countless trial & error sessions trying to find what works without at least some basis on what might work. But I guess it never hurts to try.

Wyandotte, I also read that the ladder-line should be straight in the manual, but wasn't sure if it made a significant difference. I would think it changes the characteristic impedance a bit, which the tuner would "fix". I really wanted to just trim the ladder-line length to about 10 feet and solder my own connector on it. I'm already pressed for space so 32 feet would just get in the way. On another note, you make having contacts sound so easy. I've got a RadioShack DX-402 Shortwave receiver and have yet to hear anyone/anything with it (short of noise & interference), even with the optional antenna (the one that terminates to a 3.5mm jack, guess it's considered a long-wire antenna). So that's why I felt I needed to just grab something that other people use so so I could get a little taste of some HF, even with my restrictions.

hoser, I guess now I should say "there's a dipole under my bed" - but that wouldn't make sense in my case 'cause my 'bed' is just a mattress on the floor!
 
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k8mcn

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rfradioconsult has it right !!!!!!!!!!!!! make your own dipole to listen and but the g5rv in the closet for a while...................the ladder line should be perpindicular to the dipole when you do put up the g5rv
listen to 20 meters in the day and try listening to 80 in the evenings, get a hang of whats out there and you'll soon become familiar with procedure by listening.................

Get a decent SWR meter before you try and transmit with the g5rv-find out where its resonant, and if its not , you will have to get a tuner if the swr is to far out..................
 
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Good thing about the IC-718 is it has an internal SWR meter, however, I still need a tuner (or balun) if I were to use the ladder-line without any coax between the transmitter & antenna. I ended up going with an MFJ-971 which has balanced & unbalanced inputs.

I'm still waiting on my Chinese power supply so I can't do much yet....
 

ka3jjz

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Be very aware of RF in the shack and RF exposure limits...anyone coming in contact, even accidentally, with the ladder line while you're on the air could get seriously burned. Safety first!

Good luck with the indoor shack....73s Mike
 
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