Handheld Ultralight FM DXing Directional Antenna?


Johnny
 

Hi all,

Anyone experiment with portable FM DXing antennas that can be packed for DXing field trips?

Like a handheld Yagi or something else?

Just wondered what (if anything) is out there, or if what I'm proposing would even be practical?


Johnny


Paul Blundell
 

Hi Johnny,

In the past I had considered getting a small FM Yagi and mounting this to a portable tripod but I never got very far with it.

Paul

On Tue, May 4, 2021 at 9:00 AM Johnny via groups.io <jlochey=yahoo.com@groups.io> wrote:
Hi all,

Anyone experiment with portable FM DXing antennas that can be packed for DXing field trips?

Like a handheld Yagi or something else?

Just wondered what (if anything) is out there, or if what I'm proposing would even be practical?


Johnny



--
Paul


Phillips
 

The problem with portable Yagi's is that the physical dimensions are dependent on the wavelength of the signals of interest.   Those handhelds that you see used by wildlife trackers are smaller than FM Yagi's because they are operating at higher frequencies than those of the FM band.

If we take the midpoint of the FM band as about 100MHz, then the wavelength is about 3M and this means that the width of the active elements must be about 1.5M.  If a reflector is used then it would be about 5-10% wider.  Any directors would be about 5-10% narrower.

The length of the antenna varies according to the wavelength, the number of elements and antenna characteristics but you can assume that the antenna would be about .75 wavelengths or 2.25M long.

One technique for folding Yagi's would be to use light-gauge telescoping tube for the backbone and the horizontal elements.  The backbone could be broken down into two sections and each horizontal element could consist of a short piece across the backbone with correct-length inserts to make up the element width.  
Only the active element needs a space between the two halves of the element, the reflectors and directors join in the middle. 

The backbone does not need to be a conductor, it can be any material strong enough to do the job.


From: main@UltralightDX.groups.io <main@UltralightDX.groups.io> on behalf of Paul Blundell <tanger32au@...>
Sent: Tuesday, 4 May 2021 9:40 AM
To: main@ultralightdx.groups.io <main@ultralightdx.groups.io>
Subject: Re: [UltralightDX] Handheld Ultralight FM DXing Directional Antenna?
 
Hi Johnny,

In the past I had considered getting a small FM Yagi and mounting this to a portable tripod but I never got very far with it.

Paul

On Tue, May 4, 2021 at 9:00 AM Johnny via groups.io <jlochey=yahoo.com@groups.io> wrote:
Hi all,

Anyone experiment with portable FM DXing antennas that can be packed for DXing field trips?

Like a handheld Yagi or something else?

Just wondered what (if anything) is out there, or if what I'm proposing would even be practical?


Johnny



--
Paul


Paul B. Walker, Jr.
 

I’ve FM DXed before using a Kathrein Scala 5 element yagi meant for transmitting 88-98mhz.. its used by broadcasters in the US for low power rebroadcasters or distant off air pick ups.

I’ve had at least one broadcast engineer and someone at the antenna company tell me an antenna cut for Tx for one part of the band will see equal performance across most of the entire band except maybe a slightly noticeable drop at the very end of each side of the band.

But if you’re after Eskip that won’t matter much

Go big or go home I say.  

On Mon, May 3, 2021 at 5:41 PM Phillips <phillicom@...> wrote:
The problem with portable Yagi's is that the physical dimensions are dependent on the wavelength of the signals of interest.   Those handhelds that you see used by wildlife trackers are smaller than FM Yagi's because they are operating at higher frequencies than those of the FM band.

If we take the midpoint of the FM band as about 100MHz, then the wavelength is about 3M and this means that the width of the active elements must be about 1.5M.  If a reflector is used then it would be about 5-10% wider.  Any directors would be about 5-10% narrower.

The length of the antenna varies according to the wavelength, the number of elements and antenna characteristics but you can assume that the antenna would be about .75 wavelengths or 2.25M long.

One technique for folding Yagi's would be to use light-gauge telescoping tube for the backbone and the horizontal elements.  The backbone could be broken down into two sections and each horizontal element could consist of a short piece across the backbone with correct-length inserts to make up the element width.  
Only the active element needs a space between the two halves of the element, the reflectors and directors join in the middle. 

The backbone does not need to be a conductor, it can be any material strong enough to do the job.


From: main@UltralightDX.groups.io <main@UltralightDX.groups.io> on behalf of Paul Blundell <tanger32au@...>
Sent: Tuesday, 4 May 2021 9:40 AM
To: main@ultralightdx.groups.io <main@ultralightdx.groups.io>
Subject: Re: [UltralightDX] Handheld Ultralight FM DXing Directional Antenna?
 
Hi Johnny,

In the past I had considered getting a small FM Yagi and mounting this to a portable tripod but I never got very far with it.

Paul

On Tue, May 4, 2021 at 9:00 AM Johnny via groups.io <jlochey=yahoo.com@groups.io> wrote:
Hi all,

Anyone experiment with portable FM DXing antennas that can be packed for DXing field trips?

Like a handheld Yagi or something else?

Just wondered what (if anything) is out there, or if what I'm proposing would even be practical?


Johnny



--
Paul


kevin asato
 

Ever consider a transportable 2 meter beam antenna? Or scaling one up from plans? You can construct one from steel tape measure elements using a PVC pipe or wooden broomstick for the boom which can be readily broken down for transport. (Look up direction finding antenna for example). The antennas could be handheld or mounted on a camera tripod and can be used in horizontal or vertical orientation. A 2 meter beam element length is at least 10cm/12 inches shorter than one required for the US FM broadcast band but in an area of reasonable signal, you should not notice a difference. And again, the antenna can be scaled up to whatever segment of the FM broadcast band is available in your area. (ie, Japan's FM band starts at 76MHz so will obviously be much larger)
73,
kevin
kc6pob


On Mon, May 3, 2021 at 5:10 PM Paul Blundell <tanger32au@...> wrote:
Hi Johnny,

In the past I had considered getting a small FM Yagi and mounting this to a portable tripod but I never got very far with it.

Paul

On Tue, May 4, 2021 at 9:00 AM Johnny via groups.io <jlochey=yahoo.com@groups.io> wrote:
Hi all,

Anyone experiment with portable FM DXing antennas that can be packed for DXing field trips?

Like a handheld Yagi or something else?

Just wondered what (if anything) is out there, or if what I'm proposing would even be practical?


Johnny



--
Paul


Johnny
 

Hi Kevin,

You have given me a great idea!

An antenna mounted on a tripod could be very helpful!

I may pursue that option, as I could locate it in a room or take it outside.  I'll have to think about that a bit.

Interesting idea.  I'm not big on a permanent antenna on the house.  I wouldn't want to be "tied" to that.


Thanks!


Johnny


Richard Allen
 

I don’t know if an external antenna is necessary.  My personal experience FM DXing with an ULR has been strictly with a barefoot receiver using only the attached telescopic antenna. To date I’ve logged 875 stations by Es, Ms and tropospheric modes from the Bahamas, Canada and USA.  My primary receiver is a Tecsun PL-606.

Good DX all.

Richard Allen,
near Perry OK USA.


On May 4, 2021, at 07:59, Johnny via groups.io <jlochey@...> wrote:

Hi Kevin,

You have given me a great idea!

An antenna mounted on a tripod could be very helpful!

I may pursue that option, as I could locate it in a room or take it outside.  I'll have to think about that a bit.

Interesting idea.  I'm not big on a permanent antenna on the house.  I wouldn't want to be "tied" to that.


Thanks!


Johnny


K7DWI Art
 

The easiest way to FMBC DX is using a set of old Rabbit Ears measured to the frequency you are monitoring.
Spread them at about 120 degrees.
The advantage to them is that you will be able to null out nearby FM outlets.
My YouTube video demonstrating a set of them with my Realistic DX-440 hearing and nulling out a 100KW station 85 miles away.
 https://youtu.be/69Hz1wwREFg
Attached is the measurements for the Rabbit Ears by frequency (fmdipole.txt).
Always a set in my GO Case.
73 Art K7DWI


Richard Allen
 

I’ve had no trouble nulling interfering station using the attached telescopic antenna.  I see no reason of going to the trouble of attaching a rabbit ear aerial.  It quite easy to orient the receiver to hear the signal and null out QRM.  After all this is uncomplicated ULR DXing.  Having logged 875 FM stations in a rural environment proves that an elaborate aerial system is unnecessary.

Richard Allen,
near Perry OK USA.


On May 4, 2021, at 11:00, K7DWI Art <k7dwicn82@...> wrote:

The easiest way to FMBC DX is using a set of old Rabbit Ears measured to the frequency you are monitoring.
Spread them at about 120 degrees.
The advantage to them is that you will be able to null out nearby FM outlets.
My YouTube video demonstrating a set of them with my Realistic DX-440 hearing and nulling out a 100KW station 85 miles away.
 https://youtu.be/69Hz1wwREFg
Attached is the measurements for the Rabbit Ears by frequency (fmdipole.txt).
Always a set in my GO Case.
73 Art K7DWI
<fmdipole.txt>


Paul B. Walker, Jr.
 

however, when you have room and the set up, a table top set up sure doesn't hurt.



On Tue, May 4, 2021 at 8:28 AM Richard Allen via groups.io <dx747j=me.com@groups.io> wrote:
I’ve had no trouble nulling interfering station using the attached telescopic antenna.  I see no reason of going to the trouble of attaching a rabbit ear aerial.  It quite easy to orient the receiver to hear the signal and null out QRM.  After all this is uncomplicated ULR DXing.  Having logged 875 FM stations in a rural environment proves that an elaborate aerial system is unnecessary.

Richard Allen,
near Perry OK USA.


On May 4, 2021, at 11:00, K7DWI Art <k7dwicn82@...> wrote:

The easiest way to FMBC DX is using a set of old Rabbit Ears measured to the frequency you are monitoring.
Spread them at about 120 degrees.
The advantage to them is that you will be able to null out nearby FM outlets.
My YouTube video demonstrating a set of them with my Realistic DX-440 hearing and nulling out a 100KW station 85 miles away.
 https://youtu.be/69Hz1wwREFg
Attached is the measurements for the Rabbit Ears by frequency (fmdipole.txt).
Always a set in my GO Case.
73 Art K7DWI
<fmdipole.txt>
_._,_._,_


Paul Blundell
 

That is a good point Richard, in the area I am in, it is hard to get much FM DX, unless we get some assistance over the summer months.


On Wed, May 5, 2021 at 1:26 AM Richard Allen via groups.io <dx747j=me.com@groups.io> wrote:
I don’t know if an external antenna is necessary.  My personal experience FM DXing with an ULR has been strictly with a barefoot receiver using only the attached telescopic antenna. To date I’ve logged 875 stations by Es, Ms and tropospheric modes from the Bahamas, Canada and USA.  My primary receiver is a Tecsun PL-606.

Good DX all.

Richard Allen,
near Perry OK USA.


On May 4, 2021, at 07:59, Johnny via groups.io <jlochey=yahoo.com@groups.io> wrote:

Hi Kevin,

You have given me a great idea!

An antenna mounted on a tripod could be very helpful!

I may pursue that option, as I could locate it in a room or take it outside.  I'll have to think about that a bit.

Interesting idea.  I'm not big on a permanent antenna on the house.  I wouldn't want to be "tied" to that.


Thanks!


Johnny



--
Paul


radiojayallen
 

I see merit in both approaches...it's certainly worth experimenting with, although I will say that in my over-crowded FM location I can often receive two or even three signals on a given frequency be re-orienting the whip and moving the radio. One thing though that I haven't seen discussed is that I've found many DSP FM portables don't seem to do any better with an external antenna compared with their whip unless it can be located in a better location such as on a roof, and I've wondered if this has to do with how well the .tuner's input is matched to the whip.


Paul Blundell
 

That is a good point as I have also noticed much the same, they work well with the standard whip but not much better with anything extremal.


On Wed, 5 May 2021, 20:27 radiojayallen, <radiojayallen@...> wrote:
I see merit in both approaches...it's certainly worth experimenting with, although I will say that in my over-crowded FM location I can often receive two or even three signals on a given frequency be re-orienting the whip and moving the radio. One thing though that I haven't seen discussed is that I've found many DSP FM portables don't seem to do any better with an external antenna compared with their whip unless it can be located in a better location such as on a roof, and I've wondered if this has to do with how well the .tuner's input is matched to the whip.