Icom-R75 Antenna Suggestions

[MichaelxB]

Hello all, I'm planning on getting a R-75 soon and want to be prepared by having a good antenna for it soon as possible. I usually monitor utility stations, military freqs, aircraft, number stations, hams, unknown signals, and commercial broadcasts, as well as DXing for signals. So pretty much the whole works. I'm looking for a good DXing antenna to pull in those weak signals from far away. I'm able to run a antenna outside as I live in a rural area, and can place it high up as I want.

I'd like the antenna range to be from 1000khz to 30000khz, if possible

And I'd like to keep it the $40-85 range, as I don't really want/need to spend that much on a antenna.

So tell me all, what can you recommended me to get, what do you think would be the best for my needs?
Thanks

 

[ka3jjz]

Do you know how to properly solder connections? Just how involved would you be willing to get?

With a large area, it's possible to put several antennas, in different directions. If it were me, I'd have different types of antennas as well, as what is heard poorly on one antenna, might come in better on another simply because of how propagation is working that day.

You could, for example, take a PAR antenna, discard the flexweave wire it comes with, and replace it with something longer - say 100 or 200 foot (watch this - the longer the wire, the more directional it will become off its ends on some frequencies...). Put one up as a horizontal L configuration, another as a sloper (this is all basically described in the manual for the antenna...). Or have one as a standard horizontal L, put up another antenna as an Inverted V fed with twin lead to a 4:1 balun. Or put up several Ls in different directions.

There are so many possibilities here - how much acreage are we talking about here? - that it's hard to make solid recommendations. Experimentation is a real plus here - after all, that's how you learn. To start, we have several links in our HF Antennas wiki...check out the Homebrew and Technical section of

HF Antennas - The RadioReference Wiki

Even a nice delta loop or skyloop would be a possibility here, if you have the space for one. Don't turn down wire antennas used by hams too quickly - a little math and adjustments in the design, and it will work just fine for listening, too. Just stay away from those that have traps in the antenna - they will attenuate frequencies that are outside of their designed ranges.

And as a side note - for frequencies below about 1700 Khz or so, loops are the preferred antenna, unless you have the room for VERY long antennas (several hundred to 1000 foot not out of the question here).

Oh and one more thing - learn about grounding, if you don't know this already....

So many possibilities here....Mike

 

[ka3jjz]

I would be more than remiss if I didn't recommend the ARRL Antenna handbook, any of the books from the Radio Society of Great Britain or any of Joe Carr's books...

Antenna Books

and there's also this...

Wire Antennas at Hard Core DX.com

And as a sample of Joe's writing, see the selected writings stored in PDF here...

Joe Carr Tech Notes - DXing.com

Mike

 

[MichaelxB]

Do you know how to properly solder connections? Just how involved would you be willing to get?

With a large area, it's possible to put several antennas, in different directions. If it were me, I'd have different types of antennas as well, as what is heard poorly on one antenna, might come in better on another simply because of how propagation is working that day.

You could, for example, take a PAR antenna, discard the flexweave wire it comes with, and replace it with something longer - say 100 or 200 foot (watch this - the longer the wire, the more directional it will become off its ends on some frequencies...). Put one up as a horizontal L configuration, another as a sloper (this is all basically described in the manual for the antenna...). Or have one as a standard horizontal L, put up another antenna as an Inverted V fed with twin lead to a 4:1 balun. Or put up several Ls in different directions.

There are so many possibilities here - how much acreage are we talking about here? - that it's hard to make solid recommendations. Experimentation is a real plus here - after all, that's how you learn. To start, we have several links in our HF Antennas wiki...check out the Homebrew and Technical section of

HF Antennas - The RadioReference Wiki

Even a nice delta loop or skyloop would be a possibility here, if you have the space for one. Don't turn down wire antennas used by hams too quickly - a little math and adjustments in the design, and it will work just fine for listening, too. Just stay away from those that have traps in the antenna - they will attenuate frequencies that are outside of their designed ranges.

And as a side note - for frequencies below about 1700 Khz or so, loops are the preferred antenna, unless you have the room for VERY long antennas (several hundred to 1000 foot not out of the question here).

Oh and one more thing - learn about grounding, if you don't know this already....

So many possibilities here....Mike

Thanks for the response. But if I have several antennas, how would I go about connecting them to each other? And what antennas would you recommend connecting together? (Though I'd like to keep it under $110 if I can)

I have about 31 acres of land, but I don't really want to spread out antennas too far, but am willing to a bit.

Currently I just have a random wire strung up on the house, and I know about grounding a bit. I made a thread awhile back asking about it, and pretty sure you replied.

But I need more guidance on antennas right now.

 

[MichaelxB]

What is this horizontal L and Inverted V design you speak of?
And what exactly is a twin lead?

Also, it may sound dumb, but what exactly is a balun, and its purpose?
Complete amateur here, sorry. But I like to learn and figure these things out.

 

[Token]

Thanks for the response. But if I have several antennas, how would I go about connecting them to each other? And what antennas would you recommend connecting together? (Though I'd like to keep it under $110 if I can)

In general you do not connect antennas together. This tends to result in a hodge podge of performance, degrading the performance in the sections of spectrum the antenna was made for.

Instead you use multiple antennas individually. A switch, or series of switches, can be installed to allow you to select each antenna, and then you cycle the antennas to find which works best for a particular signal.

Theory is all well and good, and I am all for solid science, but it is sometimes surprising how an antenna not meant for a specific band or application will pull a signal out better than the antenna designed for that use.

I have about 31 acres of land, but I don't really want to spread out antennas too far, but am willing to a bit.

Currently I just have a random wire strung up on the house, and I know about grounding a bit. I made a thread awhile back asking about it, and pretty sure you replied.

But I need more guidance on antennas right now.

Building wire antennas can be inexpensive. The primary cost is supports (poles) and feedline (coax). The nice thing is these items can be reused. So if you try an antenna and it does not work great you can use these parts to try a different antenna design.

An important factor to remember is that conditions change, and comparisons should be made under like conditions. If you build an antenna and it does not seem to work as well as the last one, are you sure the basic conditions are the same? Are you checking the same frequencies at about the same time of day? Have propagation conditions changed and the station you checked last time is simply not coming in, regardless of which antenna you had?

Research dipole antennas, wire antennas, longwire antennas, random wire antennas, beverages, sky loops, and inverted V's. Looking at these types of things will start to familiarize you with some of the basic principals. Then you can develop more specific questions and build a more informed question base.

There is no one silver bullet antenna. No one can tell you "put up an XYZ antenna, they do everything best" because there is just not such an animal. Some antennas do one thing well, at the cost of something else. Some antennas do everything a little bit, but nothing well. S decide what you want the antenna to do ("receive everything great" is not an option), what bands, what target signals, what size limits, etc, then people can make suggestions on what to look at as a possible solution.

T!

 

[ka3jjz]

Since a picture can be worth a thousand words, I came up with a few...the horizontal L (This is a term you might find in some European publications - it's more properly known as the 'inverted L') is a very basic antenna that many people start off with. You can ignore the tuner at the bottom of this pic - in many cases, you simply won't need it... (by the way, all links are always blue). It's presented with a formula to use at a specific frequency, but for listening, it can be as long (or short) as you wish. Just keep in mind that the longer the antenna, the more it will favor signals coming from its ends...

MFJ Enterprises Inc.

And for examples of Inverted Vs and Slopers

other wires

The famous PAR End Fed antennas

Par EndFedZ® Antennas | LNR Precision Par EndFedz Antennas and QRP Transceivers

It may not be clear as to why one antenna might perform better on one day than another. It has a great deal to do with a phenomenon we call 'propagation'. This is how a signal on HF gets from one point to another. It's far from a perfect reflector (in fact, signals in this range are refracted, not reflected - there is some energy that gets lost to space) and is greatly influenced by what is happening on the sun. This website (you will need to enable your Flash player for this) gives you a very good introduction into this topic...

Propagation Primer - Flash Movie by AE4RV

How your antenna will react to a given signal will be, in part, influenced by this. You could have a signal that is coming from a great distance away, where one antenna won't hear it so well, but another might. When you have the option, having 2 or more antennas of different types gives you another possible way to hear it.

As Token correctly suggests, start doing some research on antennas. The links I gave earlier for the ARRL antenna book and other publications are a great way to start. This is not a simple topic - there are many different antenna types, and you won't damage your receiver in any way if an antenna doesn't seem to be working very well. As he stated, you will very likely be able to reuse those parts for something else.

Mike

 

[w2xq]

31 acres? It would be a sin not to install one or more Beverage antennas for listening to LW, MW and SW up to a nominal 7 MHz. Grab my 'About The Beverage' article from http://w2xq.com/bibliography.html for an easy how-to. I don't have a direct link to the PDF, but it is under the group of articles in 73 Magazine toward the bottom of the page.

If you have a high object (tree?) to toss a rope over, I would add a vertical wire to take advantage of low-angle signals. The longer the better, but keep the run reasonably vertical.

With 31 acres, IMHO you do not have to be forced into buying limited-space expensive commercial antennas.

Have fun. HTH.

 

[MichaelxB]

In general you do not connect antennas together. This tends to result in a hodge podge of performance, degrading the performance in the sections of spectrum the antenna was made for.

Instead you use multiple antennas individually. A switch, or series of switches, can be installed to allow you to select each antenna, and then you cycle the antennas to find which works best for a particular signal.

Theory is all well and good, and I am all for solid science, but it is sometimes surprising how an antenna not meant for a specific band or application will pull a signal out better than the antenna designed for that use.



Building wire antennas can be inexpensive. The primary cost is supports (poles) and feedline (coax). The nice thing is these items can be reused. So if you try an antenna and it does not work great you can use these parts to try a different antenna design.

An important factor to remember is that conditions change, and comparisons should be made under like conditions. If you build an antenna and it does not seem to work as well as the last one, are you sure the basic conditions are the same? Are you checking the same frequencies at about the same time of day? Have propagation conditions changed and the station you checked last time is simply not coming in, regardless of which antenna you had?

Research dipole antennas, wire antennas, longwire antennas, random wire antennas, beverages, sky loops, and inverted V's. Looking at these types of things will start to familiarize you with some of the basic principals. Then you can develop more specific questions and build a more informed question base.

There is no one silver bullet antenna. No one can tell you "put up an XYZ antenna, they do everything best" because there is just not such an animal. Some antennas do one thing well, at the cost of something else. Some antennas do everything a little bit, but nothing well. S decide what you want the antenna to do ("receive everything great" is not an option), what bands, what target signals, what size limits, etc, then people can make suggestions on what to look at as a possible solution.

T!

Since a picture can be worth a thousand words, I came up with a few...the horizontal L (This is a term you might find in some European publications - it's more properly known as the 'inverted L') is a very basic antenna that many people start off with. You can ignore the tuner at the bottom of this pic - in many cases, you simply won't need it... (by the way, all links are always blue). It's presented with a formula to use at a specific frequency, but for listening, it can be as long (or short) as you wish. Just keep in mind that the longer the antenna, the more it will favor signals coming from its ends...

MFJ Enterprises Inc.

And for examples of Inverted Vs and Slopers

other wires

The famous PAR End Fed antennas

Par EndFedZ® Antennas | LNR Precision Par EndFedz Antennas and QRP Transceivers

It may not be clear as to why one antenna might perform better on one day than another. It has a great deal to do with a phenomenon we call 'propagation'. This is how a signal on HF gets from one point to another. It's far from a perfect reflector (in fact, signals in this range are refracted, not reflected - there is some energy that gets lost to space) and is greatly influenced by what is happening on the sun. This website (you will need to enable your Flash player for this) gives you a very good introduction into this topic...

Propagation Primer - Flash Movie by AE4RV

How your antenna will react to a given signal will be, in part, influenced by this. You could have a signal that is coming from a great distance away, where one antenna won't hear it so well, but another might. When you have the option, having 2 or more antennas of different types gives you another possible way to hear it.

As Token correctly suggests, start doing some research on antennas. The links I gave earlier for the ARRL antenna book and other publications are a great way to start. This is not a simple topic - there are many different antenna types, and you won't damage your receiver in any way if an antenna doesn't seem to be working very well. As he stated, you will very likely be able to reuse those parts for something else.

Mike

Sorry for all the novice questions, but I have zero experience with antennas. I'm just a shortwave listener and only been in the radio game for about a year now. I'm coming from a tecsun Pl-600 with a random length (about 40 ft) 18 gauge copper wire just alligator clipped to its telescopic antenna, pretty simple setup. Since I'm getting a pretty decent receiver here, I want a quality antenna to go along with it.

But, it seems most people recommend a Par EndFedZ antenna for a Icom R75, and from the description of it looks like a pretty good antenna with positive reviews. It seems like I could just do with it what I'm now doing with my tecsun, connect to receiver, run it out the window, and then run it up to the top of the old Cable TV antenna. And ground it of course.
But for some reason I feel like I'm not going to get much better results, or is that just me?

 

[ka3jjz]

You're forgetting about the transformer that's on one end of the PAR. Without getting heavily into the theory, this antenna would be less prone to picking up local noise sources within the house, as well as isolating the coax from the rest of the antenna (in some situations, this is desirable because it can effect the reception pattern of the antenna, as well as making sure the coax itself doesn't pick up noise and conduct it). Keep in mind that you can detach the 45 foot of wire the PAR comes with, and put on longer lengths if desired.

You can achieve something somewhat similar by putting a 9:1 transformer (sometimes called a magnetic longwire balun) in between your R75 and antenna. These are available commercially or you can build this yourself. Google will show you many such devices, and there are a few links in the HF Antennas wiki, the link for which I gave earlier.

Of course whatever antenna you put up, be sure to get it as far away from the home (and all those nasty noise sources) as you can.

One thing I would do as soon as you can is get that antenna off the whip. There is a significant risk here of a simple static charge blowing the amplifier that's usually at the end of the whip. Blow this amplifier, and the radio will go deaf. There's a pretty simple solution for this, and here's one of them...

http://forums.radioreference.com/receive-antennas-below-30mhz/295299-great-first-timer-project.html

A simple lead from the output of this box to the antenna jack on the PL-660 and you're good to go. If there is a static zap, the box will take it first - and it's a heckuva lot simpler to repair it.

I think it's clear that a little education is needed before you proceed. Take a look at the links that Tom and I gave in earlier messages. Sit down and start reading. You have a tremendous amount of space that you can use - now you must decide what kind of antenna(s) you want to build. A little book learning will start you down that road

Mike

 

[MichaelxB]

You're forgetting about the transformer that's on one end of the PAR. Without getting heavily into the theory, this antenna would be less prone to picking up local noise sources within the house, as well as isolating the coax from the rest of the antenna (in some situations, this is desirable because it can effect the reception pattern of the antenna, as well as making sure the coax itself doesn't pick up noise and conduct it). Keep in mind that you can detach the 45 foot of wire the PAR comes with, and put on longer lengths if desired.

You can achieve something somewhat similar by putting a 9:1 transformer (sometimes called a magnetic longwire balun) in between your R75 and antenna. These are available commercially or you can build this yourself. Google will show you many such devices, and there are a few links in the HF Antennas wiki, the link for which I gave earlier.

Of course whatever antenna you put up, be sure to get it as far away from the home (and all those nasty noise sources) as you can.

One thing I would do as soon as you can is get that antenna off the whip. There is a significant risk here of a simple static charge blowing the amplifier that's usually at the end of the whip. Blow this amplifier, and the radio will go deaf. There's a pretty simple solution for this, and here's one of them...

http://forums.radioreference.com/receive-antennas-below-30mhz/295299-great-first-timer-project.html

A simple lead from the output of this box to the antenna jack on the PL-660 and you're good to go. If there is a static zap, the box will take it first - and it's a heckuva lot simpler to repair it.

I think it's clear that a little education is needed before you proceed. Take a look at the links that Tom and I gave in earlier messages. Sit down and start reading. You have a tremendous amount of space that you can use - now you must decide what kind of antenna(s) you want to build. A little book learning will start you down that road

Mike

Yes it's obvious I need more education on antennas. I'll use my free time to read up on antenna types & antenna designs to get more familiar with the designs and how they work and which is best for me. Thanks for the advice all.

 

[haleve]

Best Antennas For R-75?

This set up has given me fantastic results from my R-75 in Melville New York, I connected an MFJ-1704 four position antenna switch feeding an Apex 303WA-2 HF vertical antenna & two Par EF-SWL HF end fed horizontal antennas in opposing directions (N/S & E/W) via LMR600 coax using Amphenol PL-259 connectors exclusively, I use the MFJ switch because it offers an extra terminal for future experimental antennas & it also features a center off position grounding all antennas in the event of a lightening storm, the normal external antenna & supporting mast grounding rules still apply though, these products are available at any reputable radio supply store however I am partial to Universal Radio & the Antenna Farm for my HF needs, good luck in your quest & by all means please keep us posted as to your decision & it's ensuing results.

Apex Radio 303WA-2 Shortwave antenna. ApexRadio

Par Electronics EF-SWL End Fed Dipole SWL Antenna. Par EF-SWL.

MFJ-1704 Antenna Switche mfj-1704n mfj1704

The Antenna Farm, Your two way radio source

 

[haleve]

Also check your possible future purchase selections in Eham reviews to read the results & opinions of existing & former equipment users.


eHam.net Reviews

 

[osros]

I like to add my preference if you looking for an Antenna to add. I done very well with this one it is wideband but I have used it for HF and done very well with it back in my R71A days.

AOR SA7000 Wideband Antenna

I plan to put one of these up again when my shack is done...Just FYI

 

[ka3jjz]

Keep in mind that the OP has 31 acres (yes you read that right) to play with. There's lots of space for different kinds of antennas. While limited space antennas have their place, when you have this much room, it's kinda an invitation to go big...or go home...

Mike

 

[haleve]

31 Acres VS. $85.00 Hmmmm

His budget is $85.00 & he's just starting out, even going the DIY route I don't think he's ready to compete with a HAARP antenna farm, well at least not just yet.

High Frequency Active Auroral Research Program - Wikipedia, the free encyclopedia

 

[ka3jjz]

No not yet, but give him some time...and it is almost winter, after all....Mike

 

[ridgescan]

The "horizontal L" configuration is pretty much what I ran and isn't a commonly practised setup. It is basically fed at one end, runs north to a halfway point, turns on a non-conductive mast to run the second half west, with the far end attached to another non-conductive mast.. RF doesn't see it as an L but just as a 100' wire bent due to space restriction. It did some nice reception for me for a while.
I tried an inverted L-didn't do well here because of too much noise.
My suggestion is-the random wire you have now-how are you feeding it? I would feed it with 50 ohm coax, and ground that coax near the point of entry to the shack. This will help to quiet noise by giving you a counterpoise to that wire. The "other half". Maybe you will see a better result.
Otherwise, since you can, expand that wire, feed it the same way, but run it in an upward slope to the top of a tree at say 100-150' away (Sloper). You have the space-take advantage. Orient it east-west (ends north south, broads east west) Have fun!
Plan a whole day where you just experiment with different configurations and end up with the best result.

 

[MichaelxB]

His budget is $85.00 & he's just starting out, even going the DIY route I don't think he's ready to compete with a HAARP antenna farm, well at least not just yet.

High Frequency Active Auroral Research Program - Wikipedia, the free encyclopedia

Glad someone understands that. I'm still in the learning process for antennas! A lot of what I'm reading is mumbo jumbo to me, though I'm young & inexperienced. I learn better by visuals, or asking direct questions.

 

[MichaelxB]

Questions about Par EndFedZ

Alright all, bear with me. Due to its affordability and such, I think I'm going to go with the Par EndFedZ antenna. Like someone above mentioned I don't have the money or experience to set a HAARP antenna farm . . yet.

I've been looking at the "inverted L" design for a Par EndFedZ antenna and wondering if it would work well for this antenna? A lot say it performs well on certain bands only.. does anyone know if it will have good reception on all bands? Something like this here - http://www.hamuniverse.com/w7lninvertl.GIF

Or will that not work or is there a better way?