G5RV vs G5RVjr
- Thread starter W2MR
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Just depends on what bands you want to be able to use. The 'Jr' just isn't going to be that usable on 80 meters, for instance. You also have to keep in mind that any G5RV is a compromise antenna on any band except the -one- band it was designed for. Nothing new about that. Which would be most -practical- for you?
- 'Doc
- 'Doc
I know your question is about the G5RV, but since both are a compromise... Have you considered a vertical antenna? I'm thinking you may find more utility in the vertical over the Jr dipole. Just a thought.
But to answer your question, you could probably do well with the G5RVjr. If you're interested in 80m you might be able to use coils on the ends to electronically lengthen your smaller antenna. If your interests are 10 - 40 meters, and you have a good antenna tuner the G5RVjr will probably suit.
You still want it up 40 - 50 feet a vertical might suit your needs as well. Hope this helps.
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But to answer your question, you could probably do well with the G5RVjr. If you're interested in 80m you might be able to use coils on the ends to electronically lengthen your smaller antenna. If your interests are 10 - 40 meters, and you have a good antenna tuner the G5RVjr will probably suit.
You still want it up 40 - 50 feet a vertical might suit your needs as well. Hope this helps.
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The G5RV was designed as a 20m antenna with a little gain that matches to 75ohm coax and it just happens to work fine on 80 through 10m although 80m is down a bit. The G5RV JR is half size and would work best on 10m and is useable 40 through 10 or even 6m and 40m will suffer a bit.
The critical length of balanced line on either antenna only comes into play on the one band the antenna was designed for and all other bands the antenna is a random doublet with a chunk of balanced feedline. If you connect the balanced line directly to a tuner it will be an efficient antenna on all bands within its useable range but when you attach coax you incur some major coax losses on most bands, especially the lowest.
You might look into an antenna called a ZS6BKW which is a modern day computer designed cousin of the G5RV that actually has a good match to 50ohms on 40, 20, 17, 12, 10 and 6m without a tuner. This means it will not incur the same major coax loss compared to a G5RV. It also works about the same as a G5RV on 80m with a tuner and its 94ft long with about 40ft of critical length ladder line depending on the type used.
You can bend any of these antennas somewhat to fit your property and if you like operating on 40 and 80m you really want the larger size antenna rather than a G5RV JR. Here is one of the many sites with info on building a ZS6BKW. http://www.w5ddl.org/files/Zs6bkw_vs_G5rv_20100221b.pdf
I used to use G5RVs a lot until I discovered the BKW and now use them in many locations and am very happy with their performance.
For most people these types of antennas will be mounted mostly horizontal from 15 to 30ft in the air and they work great for NVIS on 80/40m and also work DX just fine but the higher the better for that.
At one location I have a ZS6BKW at about 25ft height and a DX Engineering 43ft vertical with a significant amount of ground radials and the 43ft vertical works better on 40 and 20m DX but the ZS6BKW is much better on 80m local or DX and better on 40m local and sometimes better on other bands depending on the direction. If I could keep only one antenna at that location it would be the ZS6BKW.
The 43ft vertical cost a couple of hundred bucks and the ZS6BKW was maybe $25 in parts.
prcguy
The critical length of balanced line on either antenna only comes into play on the one band the antenna was designed for and all other bands the antenna is a random doublet with a chunk of balanced feedline. If you connect the balanced line directly to a tuner it will be an efficient antenna on all bands within its useable range but when you attach coax you incur some major coax losses on most bands, especially the lowest.
You might look into an antenna called a ZS6BKW which is a modern day computer designed cousin of the G5RV that actually has a good match to 50ohms on 40, 20, 17, 12, 10 and 6m without a tuner. This means it will not incur the same major coax loss compared to a G5RV. It also works about the same as a G5RV on 80m with a tuner and its 94ft long with about 40ft of critical length ladder line depending on the type used.
You can bend any of these antennas somewhat to fit your property and if you like operating on 40 and 80m you really want the larger size antenna rather than a G5RV JR. Here is one of the many sites with info on building a ZS6BKW. http://www.w5ddl.org/files/Zs6bkw_vs_G5rv_20100221b.pdf
I used to use G5RVs a lot until I discovered the BKW and now use them in many locations and am very happy with their performance.
For most people these types of antennas will be mounted mostly horizontal from 15 to 30ft in the air and they work great for NVIS on 80/40m and also work DX just fine but the higher the better for that.
At one location I have a ZS6BKW at about 25ft height and a DX Engineering 43ft vertical with a significant amount of ground radials and the 43ft vertical works better on 40 and 20m DX but the ZS6BKW is much better on 80m local or DX and better on 40m local and sometimes better on other bands depending on the direction. If I could keep only one antenna at that location it would be the ZS6BKW.
The 43ft vertical cost a couple of hundred bucks and the ZS6BKW was maybe $25 in parts.
prcguy
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It is possible to make a useable antenna about the same size as a G5RV Jr if you run balanced feedline from the antenna all the way to a balanced tuner.
A local 80m morning group has a guy with a 50ft long dipole (25ft per leg) up at 30ft and fed with home made open wire line with about 6" spacing all the way from the antenna to a balanced tuner at his radio. He is as loud or louder than others in the group and everyone is running the same power and are at similar distance to me.
A 50ft total length dipole is not going to be terribly efficient on 80m but the super low loss feedline avoids additional loss that other type antennas will incur at high VSWR like a full size G5RV used on 80m. If your willing to commit to low loss open wire line and a good tuner you can work a lot of bands with a fairly small wire antenna.
prcguy
A local 80m morning group has a guy with a 50ft long dipole (25ft per leg) up at 30ft and fed with home made open wire line with about 6" spacing all the way from the antenna to a balanced tuner at his radio. He is as loud or louder than others in the group and everyone is running the same power and are at similar distance to me.
A 50ft total length dipole is not going to be terribly efficient on 80m but the super low loss feedline avoids additional loss that other type antennas will incur at high VSWR like a full size G5RV used on 80m. If your willing to commit to low loss open wire line and a good tuner you can work a lot of bands with a fairly small wire antenna.
prcguy
I have a G5RV jr up, and with the exception of 20m (and 17m), if you want to work more that that, especially 40m, go with the full size G5RV. Mine does 20m and 17m great, and is ok on 12 and 10 (when open), but on 30 and 40, it's pretty much deaf. Much of this has to do with the fact I can only get it up about 20 feet at the moment. Im researching better options, but for now, especially as I mostly work only 20m, this is ok for the time being.
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