just purchased this reciever,just starting out in this hobby,is there an antenna that will work on all bands of this reciever?
Icom R-75 antenna?
- Thread starter cmed325
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Wow, that is a very hard question to answer since so much depends on your needs and environment, and there are so many options you can take, from store-bought, to homebrew.
Be sure to stop by the Antenna forum here, and also take a look at the wiki:
Antennas - The RadioReference Wiki
The short answer is that a simple 10-foot piece of random wire will work on all frequencies the R75 is capable of - but perhaps not well enough for your needs.
To get started however, the R75 makes it easy with both a 50-ohm input, AND a high-impedance input with a built-in 9:1 transformer useful for directly attaching random wires. The random wire may not be ideal if you are indoors near a noise source.
Make sure that if you are trying different antennas on both of the 50-ohm and Hi-Z inputs, that you select the right port via the keyboard on the R75 between antenna 1 and antenna 2.
Perhaps ask this question in the antenna forum with a bit of detail about your environment - do you have acres of land, or are you in an apartment? Do you prefer store-bought, or are you up for some home-brew? That kind of thing will get your R75 singing!
Be sure to stop by the Antenna forum here, and also take a look at the wiki:
Antennas - The RadioReference Wiki
The short answer is that a simple 10-foot piece of random wire will work on all frequencies the R75 is capable of - but perhaps not well enough for your needs.
To get started however, the R75 makes it easy with both a 50-ohm input, AND a high-impedance input with a built-in 9:1 transformer useful for directly attaching random wires. The random wire may not be ideal if you are indoors near a noise source.
Make sure that if you are trying different antennas on both of the 50-ohm and Hi-Z inputs, that you select the right port via the keyboard on the R75 between antenna 1 and antenna 2.
Perhaps ask this question in the antenna forum with a bit of detail about your environment - do you have acres of land, or are you in an apartment? Do you prefer store-bought, or are you up for some home-brew? That kind of thing will get your R75 singing!
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Fast1eddie
Member
Take a look at the Par SWL End Fed long wire. I have had mine up for about 3 years with no trouble at all. Excellent and "quiet" reception, this antenna comes with a impedance matching network that is user adjustable. I installed mine for SE and NE reception. Amazingly, I have monitored maritime and aviation traffic from the Pacific side. QTH is outside of Pittsburgh.
My wire feeds a Kenwood R2000 and a AOR 5000 through a passive single input dual output combiner.
Let us know how you worked this out.
My wire feeds a Kenwood R2000 and a AOR 5000 through a passive single input dual output combiner.
Let us know how you worked this out.
would this antenna work well if i ran it in my attic?
+1 for the PAR -- I don't use it but it's a simple design that works. For the lower frequencies, you may need more wire -- which you can add to or replace on the PAR since it comes with the 9:1 balun.
Just be sure to buy some good quality coax -- RG8 is O.K. to start out with but I would recommend LMR400 if your budget allows. You shouldn't need more than 50ft of coax -- and the shorter the better. When you get longer than 50ft, the cost will rise quite a bit. (You're better off moving your antenna around if you need more than 50ft of coax.)
Here's a good place to view antennas, including the PAR:
Shortwave Antennas
Just be sure to buy some good quality coax -- RG8 is O.K. to start out with but I would recommend LMR400 if your budget allows. You shouldn't need more than 50ft of coax -- and the shorter the better. When you get longer than 50ft, the cost will rise quite a bit. (You're better off moving your antenna around if you need more than 50ft of coax.)
Here's a good place to view antennas, including the PAR:
Shortwave Antennas
Token
Member
The R75 is not like a scanner, as such you really cannot pick one "all band" antenna for it that works equally well on "all bands". Even though it is only 60 MHz of frequency it still covers many, many bands, in fact a couple of complete pieces of spectrum (LW, MW, HF, and part of VHF). A scanner might easily cover 420 to 470 MHz, and that is 50 MHz, and a single antenna will cover 420 to 470 MHz very well. But when you look at the bandwidth as a ratio of frequency (and you must do so when designing an antenna) you can really equate that entire UHF band to one small chunk of HF, for simple math lets call it 4.200 to 4.700 MHz, only 0.5 MHz.
For antenna design function, with regard to bandwidth, these two radically different bands are very similar in limitations.
So, to cover the popular VHF/UHF scanner bands you can design a single antenna, pretty easily, to work 30-50 MHz, 140-175 MHz, 420-470 MHz, and 900 MHz. Sure, it will not work very well between these bands, but relatively few people spend a lot of time "between" the popular bands on VHF/UHF. Yes, I know I am leaving out important things like the VHF aviation band and the UHF mil-air band, but I am using this as an example, not as an all encompassing.
Before someone says "discone", the discone is a compromise antenna that does nothing well, but does a lot of things OK. It is often quoted as a "unity gain " antenna, but in fact it is not really unity gain across most of its typical operating range as applied to VHF/UHF scanners, it is unity gain in its most efficient ranges only. And yes they can be built and used on HF frequencies as well, with the associated size increase, think one 30 to 50 feet high as a good starting place, taller if you really want to cover the entire MW/HF range.
But, the range covered by the R75 is 30 kHz (0.03 MHz) to 60 MHz. And in very real terms almost the entire range is used, with few gaps as found on VHF/UHF. You could equate, for purposes of antenna design and bandwidth as a function of frequency covered, this to a "scanner" that covered 30 MHz to 60000 MHz (yes, that is sixty thousand MHz) and trying to find one antenna to do that entire range with no gaps. It just ain't gonna happen with flat, equal, performance across the entire range.
So more typically with a radio like the R75 and a situation when you can only have one antenna you pick the part of the spectrum covered that you are most interested in. Say the Marine bands in the 8 and 10 MHz range. You build/buy an antenna optimized for those ranges and you accept that it might not work quite as well, but will still work, in other ranges. It is possible to pick a "wider" banded antenna, one that maybe works 5 to 25 MHz, or even 3 to 30 MHz, but given the same amount of cost and effort, and area, that will NEVER work as well as one designed for a smaller band within the small band that antenna is designed for.
Wide bandwidth in an HF antenna is a compromise, and compromise means it works less well in some areas, and almost as good in others.
You want "best" performance you build an antenna for each chunk of spectrum you are interested in, no "single" antenna will do it. But often one can find "acceptable" performance with a compromise design.
Some people put up multiple compromise antennas. For example one antenna for 2 MHz and down, covering LW and MW. Another antenna for 2 MHz to 7 MHz. And another antenna covering 7 MHz to 30 MHz. Then again other people only have room for one antenna, and must "make do". As a general statement the multiple antenna approach will often result in better performance, but the single antenna is often “good enough”.
As another general rule size matters with HF antennas. A full sized half wave dipole for any frequency will almost always outperform a "reduced" size half wave, say a loaded half wave, for the same frequency. And the full sized antenna will have wider bandwidth, or a larger efficient operating range. And a full sized one and one half wave antenna, with its associated larger capture area, will most often outperform a half wave dipole. If you have the selection of two antennas, both made for the same band or range of frequencies, and one is physically larger than the other, and you can support the larger size, selecting the larger antenna will almost always be the better solution.
Yeah, OK, I did not recommend any one antenna here. Realistically, with the amount of information the OP gave, one antenna cannot be recommended. How much room is there for antenna construction? Is it an apartment or a house? Is the house on a city lot or a country area with acreage? What is the cost bracket allowed for antenna purchase? Are you able and willing to build pieces parts yourself? If you can handle simple hand tools it is possible to build a relatively acceptable antenna for fairly low cost. What kinds of signals are you most interested in? Ham listening? Spy numbers? Shortwave broadcast? Military comms? HF aviation?
All of the above questions, and more, could go into selecting the "best" antenna for your application.
T!
For antenna design function, with regard to bandwidth, these two radically different bands are very similar in limitations.
So, to cover the popular VHF/UHF scanner bands you can design a single antenna, pretty easily, to work 30-50 MHz, 140-175 MHz, 420-470 MHz, and 900 MHz. Sure, it will not work very well between these bands, but relatively few people spend a lot of time "between" the popular bands on VHF/UHF. Yes, I know I am leaving out important things like the VHF aviation band and the UHF mil-air band, but I am using this as an example, not as an all encompassing.
Before someone says "discone", the discone is a compromise antenna that does nothing well, but does a lot of things OK. It is often quoted as a "unity gain " antenna, but in fact it is not really unity gain across most of its typical operating range as applied to VHF/UHF scanners, it is unity gain in its most efficient ranges only. And yes they can be built and used on HF frequencies as well, with the associated size increase, think one 30 to 50 feet high as a good starting place, taller if you really want to cover the entire MW/HF range.
But, the range covered by the R75 is 30 kHz (0.03 MHz) to 60 MHz. And in very real terms almost the entire range is used, with few gaps as found on VHF/UHF. You could equate, for purposes of antenna design and bandwidth as a function of frequency covered, this to a "scanner" that covered 30 MHz to 60000 MHz (yes, that is sixty thousand MHz) and trying to find one antenna to do that entire range with no gaps. It just ain't gonna happen with flat, equal, performance across the entire range.
So more typically with a radio like the R75 and a situation when you can only have one antenna you pick the part of the spectrum covered that you are most interested in. Say the Marine bands in the 8 and 10 MHz range. You build/buy an antenna optimized for those ranges and you accept that it might not work quite as well, but will still work, in other ranges. It is possible to pick a "wider" banded antenna, one that maybe works 5 to 25 MHz, or even 3 to 30 MHz, but given the same amount of cost and effort, and area, that will NEVER work as well as one designed for a smaller band within the small band that antenna is designed for.
Wide bandwidth in an HF antenna is a compromise, and compromise means it works less well in some areas, and almost as good in others.
You want "best" performance you build an antenna for each chunk of spectrum you are interested in, no "single" antenna will do it. But often one can find "acceptable" performance with a compromise design.
Some people put up multiple compromise antennas. For example one antenna for 2 MHz and down, covering LW and MW. Another antenna for 2 MHz to 7 MHz. And another antenna covering 7 MHz to 30 MHz. Then again other people only have room for one antenna, and must "make do". As a general statement the multiple antenna approach will often result in better performance, but the single antenna is often “good enough”.
As another general rule size matters with HF antennas. A full sized half wave dipole for any frequency will almost always outperform a "reduced" size half wave, say a loaded half wave, for the same frequency. And the full sized antenna will have wider bandwidth, or a larger efficient operating range. And a full sized one and one half wave antenna, with its associated larger capture area, will most often outperform a half wave dipole. If you have the selection of two antennas, both made for the same band or range of frequencies, and one is physically larger than the other, and you can support the larger size, selecting the larger antenna will almost always be the better solution.
Yeah, OK, I did not recommend any one antenna here. Realistically, with the amount of information the OP gave, one antenna cannot be recommended. How much room is there for antenna construction? Is it an apartment or a house? Is the house on a city lot or a country area with acreage? What is the cost bracket allowed for antenna purchase? Are you able and willing to build pieces parts yourself? If you can handle simple hand tools it is possible to build a relatively acceptable antenna for fairly low cost. What kinds of signals are you most interested in? Ham listening? Spy numbers? Shortwave broadcast? Military comms? HF aviation?
All of the above questions, and more, could go into selecting the "best" antenna for your application.
T!
N8IAA
Member
A lot depends on what portions of the .100-60MHz you'll be listening too. My suggestion is a wire antenna, like the Par EF swl, terminated to an inexpensive tuner, and then to the radio. It doesn't have to be outside. It can be in your attic. A 40m antenna can be tuned lower in frequency, or higher. It doesn't have to be expensive, or elaborate
HTH,
Larry
HTH,
Larry
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