Portable VHF antennas and rotator


John Claridge 2E0JJC
 


Hi all

I am thinking of entering the FMAC contests and therefore I will need to buy 2m and 70cms antennas. They must be suitable for portable working (Sat in my car)
I have a strong portable mast system (swaged ali poles) which can take a yagi. Any antenna recommendations from our portable contest members?

Tony (G4LDL)...I believe you use a rotator. Can you please tell me the model you use. Is it 12v or mains with an inverter unit?

Thanks in advance

John. 2E0JJC


Dom - 2E0WHQ
 

Hi John,

Strictly speaking, being the 'FM'AC, then traditionally antennas would usually be vertically polarized for FM, however, as we know, as the FMAC precedes the UKAC (SSB), most operators will just put up a single antenna (beam) if they are going to take part in both. For 2m, I use a simple Alton Moxon antenna, which does have some directional properties, but it's beam is wide enough to allow me to pick up stations which I'm not pointing directly at. A good Omnidirectional, horizontally polarized antenna is the Wimo 2m Big Wheel. That seems to give consistently good results without having to go to the effort of a beam.
For 70cm, I use a Diamond A430S10R2, which is a 10-element Yagi that gives fantastic results. It's a nice compact beam and if you want to make it smaller for packing away, then you can just undo the element wing nuts and turn the elements sideways so the antenna takes up less space.
For any beam, I would probably recommend a centre supported beam, rather than a rear-end supported beam as it puts less stress on the rotator, as the load is balanced equally.
For 2m antennas, take a look at what Diamond, EAntennas and Powabeam have to offer. It really comes down to a personal choice and an antenna which meets your size requirements. At the end of the day, all Yagi antennas are pretty much working off the same principles, Reflector, Driven Element and Directors, there is nothing mythical about them really. The more directors you have, the greater the gain, but the narrower the beam.
As for rotators, there are some 12v ones out there, but not many. There is one specific 12v supplier, whose name escapes me for the moment, but they are very expensive if I remember correctly. From a recent post in one of the Facebook contesting groups, it showed that most people either used a Leisure Battery with a 12/240V inverter and just used a mains powered rotator, or they used a generator to give them 240v for the rotator. I personally use a leisure battery and an inverter.
Welcome to contesting! I'm sure you'll get lots of varied opinions and suggestions.
73
Dom, 2E0WHQ


Tony (G4LDL)
 

Hi John.   Well currently my set up is slightly unorthodox.  I used to have a trailer with a pump up SCAM on it. For that the rotator did go on top in the “normal” fashion.

However since the SCAM pump up became defunct and I acquired a new Yaesu rotator I have a set up where the rotator sits on a plank on the ground (which was meant to be partially under the wheel but isn’t).  I then have a bar strapped to the roof rack and the poles go up through a tube fixed to this with the antenna on top.

The rotator is a “standard” Yaesu and operated from 240v – but I run a generator which also runs a 240/12v psu to drive the rig.

 

However I should say that my main target is the ACs (SSB/CW) rather than the FM section but I enter the FM as well as I am usually set up. Hence I use horizontal beam antennas – which sort of defeats the original intention of the FM bit but I’m not the only one that does it.

No reason why you shouldn’t use a vertical antenna and get it as high and in the clear as possible.  Good co-ax is a must if you don’t want to lose to much Rx signal and you might even think about a masthead preamp although they are of more benefit if you are using beams as then you can null out some of the signals which can be a problem with an omnidirectional antenna!

 

Have a chat further sometime at Club.

 

73 Tony, G4LDL.

 

 

 

 

From: sdarc@groups.io <sdarc@groups.io> On Behalf Of John Claridge 2E0JJC
Sent: 23 December 2021 18:08
To: sdarc@groups.io
Subject: [sdarc] Portable VHF antennas and rotator

 


Hi all


I am thinking of entering the FMAC contests and therefore I will need to buy 2m and 70cms antennas. They must be suitable for portable working (Sat in my car)
I have a strong portable mast system (swaged ali poles) which can take a yagi. Any antenna recommendations from our portable contest members?

Tony (G4LDL)...I believe you use a rotator. Can you please tell me the model you use. Is it 12v or mains with an inverter unit?

Thanks in advance


John. 2E0JJC


Dom - 2E0WHQ
 

The 12v rotator manufacturer I was trying to think of is SPID. Make sure you're sat down when you look at the prices. 😄

Dom, 2E0WHQ


John Claridge 2E0JJC
 

Many thanks Tony. Yes, a chat at the club will good.

John

On Thu, 23 Dec 2021, 6:52 pm Tony (G4LDL) via groups.io, <tony.ldl=ntlworld.com@groups.io> wrote:

Hi John.   Well currently my set up is slightly unorthodox.  I used to have a trailer with a pump up SCAM on it. For that the rotator did go on top in the “normal” fashion.

However since the SCAM pump up became defunct and I acquired a new Yaesu rotator I have a set up where the rotator sits on a plank on the ground (which was meant to be partially under the wheel but isn’t).  I then have a bar strapped to the roof rack and the poles go up through a tube fixed to this with the antenna on top.

The rotator is a “standard” Yaesu and operated from 240v – but I run a generator which also runs a 240/12v psu to drive the rig.

 

However I should say that my main target is the ACs (SSB/CW) rather than the FM section but I enter the FM as well as I am usually set up. Hence I use horizontal beam antennas – which sort of defeats the original intention of the FM bit but I’m not the only one that does it.

No reason why you shouldn’t use a vertical antenna and get it as high and in the clear as possible.  Good co-ax is a must if you don’t want to lose to much Rx signal and you might even think about a masthead preamp although they are of more benefit if you are using beams as then you can null out some of the signals which can be a problem with an omnidirectional antenna!

 

Have a chat further sometime at Club.

 

73 Tony, G4LDL.

 

 

 

 

From: sdarc@groups.io <sdarc@groups.io> On Behalf Of John Claridge 2E0JJC
Sent: 23 December 2021 18:08
To: sdarc@groups.io
Subject: [sdarc] Portable VHF antennas and rotator

 


Hi all


I am thinking of entering the FMAC contests and therefore I will need to buy 2m and 70cms antennas. They must be suitable for portable working (Sat in my car)
I have a strong portable mast system (swaged ali poles) which can take a yagi. Any antenna recommendations from our portable contest members?

Tony (G4LDL)...I believe you use a rotator. Can you please tell me the model you use. Is it 12v or mains with an inverter unit?

Thanks in advance


John. 2E0JJC


John Claridge 2E0JJC
 

Thanks for the info Dom. Your 70cms Diamond looks interesting and is a reasonable price.

John

On Thu, 23 Dec 2021, 6:43 pm Dom (2E0WHQ), <domwilko@...> wrote:
Hi John,

Strictly speaking, being the 'FM'AC, then traditionally antennas would usually be vertically polarized for FM, however, as we know, as the FMAC precedes the UKAC (SSB), most operators will just put up a single antenna (beam) if they are going to take part in both. For 2m, I use a simple Alton Moxon antenna, which does have some directional properties, but it's beam is wide enough to allow me to pick up stations which I'm not pointing directly at. A good Omnidirectional, horizontally polarized antenna is the Wimo 2m Big Wheel. That seems to give consistently good results without having to go to the effort of a beam.
For 70cm, I use a Diamond A430S10R2, which is a 10-element Yagi that gives fantastic results. It's a nice compact beam and if you want to make it smaller for packing away, then you can just undo the element wing nuts and turn the elements sideways so the antenna takes up less space.
For any beam, I would probably recommend a centre supported beam, rather than a rear-end supported beam as it puts less stress on the rotator, as the load is balanced equally.
For 2m antennas, take a look at what Diamond, EAntennas and Powabeam have to offer. It really comes down to a personal choice and an antenna which meets your size requirements. At the end of the day, all Yagi antennas are pretty much working off the same principles, Reflector, Driven Element and Directors, there is nothing mythical about them really. The more directors you have, the greater the gain, but the narrower the beam.
As for rotators, there are some 12v ones out there, but not many. There is one specific 12v supplier, whose name escapes me for the moment, but they are very expensive if I remember correctly. From a recent post in one of the Facebook contesting groups, it showed that most people either used a Leisure Battery with a 12/240V inverter and just used a mains powered rotator, or they used a generator to give them 240v for the rotator. I personally use a leisure battery and an inverter.
Welcome to contesting! I'm sure you'll get lots of varied opinions and suggestions.
73
Dom, 2E0WHQ


John Claridge 2E0JJC
 

Thanks Dom

SPID prices!!!....I would need to chat with my wife to see if she would agree to us taking out a mortgage 😀

John


On Thu, 23 Dec 2021, 8:18 pm Dom (2E0WHQ), <domwilko@...> wrote:
The 12v rotator manufacturer I was trying to think of is SPID. Make sure you're sat down when you look at the prices. 😄

Dom, 2E0WHQ


Marc (M0KYB)
 

I have a SPID and can highly recommend, at 12V full rotation is quite slow (about 2 mins), at 18V it is much quicker (about 60-80s). They are really well built and come with a USB controller so it is easy to integrate them with a logger so that the antenna automatically turns to the station being worked.
Marc


Den (M0ACM)
 

Feed it with rectified 240v and it is MUCH quicker .... for a brief moment !!! 

Hi hi !

Ooh this wine is good stuff !

Joyeux Nöel à tous et à toutes!
Frohe Weihnachten!
Nadolig Llawen!
...and a brill dx  fer 2022!!

Acme (hic!).




John Claridge 2E0JJC
 

Thanks for your reply Marc. Dom also mentioned the SPID models but unfortunately I struggled to find one that would not quadruple my bank overdraft.

I have now decided to go down the inverter route. 
I was aiming to buy new but I do have an old light weight Altai rotator that was given to me so I aim to connect it up to an inverter and see how it performs.
This rotator has seen better times but I am sure that Den's tip about giving it a dose of "rectified 240v" will quickly liven it up. 😀

Thanks all for your help.

John


On Sat, 25 Dec 2021, 11:48 am Marc (M0KYB), <marc@...> wrote:
I have a SPID and can highly recommend, at 12V full rotation is quite slow (about 2 mins), at 18V it is much quicker (about 60-80s). They are really well built and come with a USB controller so it is easy to integrate them with a logger so that the antenna automatically turns to the station being worked.
Marc


Den (M0ACM)
 

Hi John,

Yes, but Conficius he say " Never take ACMe's Advice on Christmas day after a few bottles of wine."
.....or, put another way "in vino very naff" !!

On a serious and more sober note, these Altai (other makes available!) rotors are fine for "lightweight"  beams (they were made to turn 700+mhz UHF TV beams in fringe areas ...now and again) but they are mighty s-l-o-w !! 

I have used them in the long distant past at home. Many a time I have heard a "juicy" station calling....very weak.... I turn the beam.... wrong way first of course (!) so by the time I have his direction, he either has a 2-hour pile up or given up and gone 'search and pounce' !

The compromise rotator for me would be the Yeasu G450. Mains, runs happily off a cheapo inverter, a decent turn of speed, not toooooo heavy for a /p mast top and generally available on the 2nd hand market. Others will comment I am sure....

The other more "enterprising" method could be a powerful 12v stepper motor, an Arduino and some code. That kind of design could wipe out other entries at next year's Construction Competition!  For /p you might not need a display as you can SEE your beam direction. Another idea to gather practical comments perhaps ...

73 and "Merry Christmas to all... and to all a Good Night's DX"

ACM




John Claridge 2E0JJC
 

Thanks for the information Den.

Your "other more "enterprising" method".....I would probably have it completed ready to participate in the 2023 contests however by then I suppose I would have saved enough pennies to buy a Yeasu G450 😀

Happy New Year to all

John


On Sun, 26 Dec 2021, 1:17 pm Den (M0ACM), <denf.acm@...> wrote:
Hi John,

Yes, but Conficius he say " Never take ACMe's Advice on Christmas day after a few bottles of wine."
.....or, put another way "in vino very naff" !!

On a serious and more sober note, these Altai (other makes available!) rotors are fine for "lightweight"  beams (they were made to turn 700+mhz UHF TV beams in fringe areas ...now and again) but they are mighty s-l-o-w !! 

I have used them in the long distant past at home. Many a time I have heard a "juicy" station calling....very weak.... I turn the beam.... wrong way first of course (!) so by the time I have his direction, he either has a 2-hour pile up or given up and gone 'search and pounce' !

The compromise rotator for me would be the Yeasu G450. Mains, runs happily off a cheapo inverter, a decent turn of speed, not toooooo heavy for a /p mast top and generally available on the 2nd hand market. Others will comment I am sure....

The other more "enterprising" method could be a powerful 12v stepper motor, an Arduino and some code. That kind of design could wipe out other entries at next year's Construction Competition!  For /p you might not need a display as you can SEE your beam direction. Another idea to gather practical comments perhaps ...

73 and "Merry Christmas to all... and to all a Good Night's DX"

ACM




Viv Williams
 

Hi John,
      Just a thought. You might want to look at the Big Wheel antennas.  Several stations have used them in the UKACs and they seem to have  good results for an omni antenna that does not need a rotator. 

The phasing looks interesting/Difficult  There are commercial ones available.

Best Regards

viv
M0IEP


On Fri, 31 Dec 2021 at 12:29, John Claridge 2E0JJC <2e0jjc@...> wrote:
Thanks for the information Den.

Your "other more "enterprising" method".....I would probably have it completed ready to participate in the 2023 contests however by then I suppose I would have saved enough pennies to buy a Yeasu G450 😀

Happy New Year to all

John

On Sun, 26 Dec 2021, 1:17 pm Den (M0ACM), <denf.acm@...> wrote:
Hi John,

Yes, but Conficius he say " Never take ACMe's Advice on Christmas day after a few bottles of wine."
.....or, put another way "in vino very naff" !!

On a serious and more sober note, these Altai (other makes available!) rotors are fine for "lightweight"  beams (they were made to turn 700+mhz UHF TV beams in fringe areas ...now and again) but they are mighty s-l-o-w !! 

I have used them in the long distant past at home. Many a time I have heard a "juicy" station calling....very weak.... I turn the beam.... wrong way first of course (!) so by the time I have his direction, he either has a 2-hour pile up or given up and gone 'search and pounce' !

The compromise rotator for me would be the Yeasu G450. Mains, runs happily off a cheapo inverter, a decent turn of speed, not toooooo heavy for a /p mast top and generally available on the 2nd hand market. Others will comment I am sure....

The other more "enterprising" method could be a powerful 12v stepper motor, an Arduino and some code. That kind of design could wipe out other entries at next year's Construction Competition!  For /p you might not need a display as you can SEE your beam direction. Another idea to gather practical comments perhaps ...

73 and "Merry Christmas to all... and to all a Good Night's DX"

ACM




John Claridge 2E0JJC
 

Thanks Viv

I have to admit I have never seen this antenna before. The article looks a very interesting read however I don't think I should study it this evening as my glass is part way through its third refill.

73

John


On Fri, 31 Dec 2021, 8:30 pm Viv Williams via groups.io, <sn67nu=googlemail.com@groups.io> wrote:
Hi John,
      Just a thought. You might want to look at the Big Wheel antennas.  Several stations have used them in the UKACs and they seem to have  good results for an omni antenna that does not need a rotator. 

The phasing looks interesting/Difficult  There are commercial ones available.

Best Regards

viv
M0IEP


On Fri, 31 Dec 2021 at 12:29, John Claridge 2E0JJC <2e0jjc@...> wrote:
Thanks for the information Den.

Your "other more "enterprising" method".....I would probably have it completed ready to participate in the 2023 contests however by then I suppose I would have saved enough pennies to buy a Yeasu G450 😀

Happy New Year to all

John

On Sun, 26 Dec 2021, 1:17 pm Den (M0ACM), <denf.acm@...> wrote:
Hi John,

Yes, but Conficius he say " Never take ACMe's Advice on Christmas day after a few bottles of wine."
.....or, put another way "in vino very naff" !!

On a serious and more sober note, these Altai (other makes available!) rotors are fine for "lightweight"  beams (they were made to turn 700+mhz UHF TV beams in fringe areas ...now and again) but they are mighty s-l-o-w !! 

I have used them in the long distant past at home. Many a time I have heard a "juicy" station calling....very weak.... I turn the beam.... wrong way first of course (!) so by the time I have his direction, he either has a 2-hour pile up or given up and gone 'search and pounce' !

The compromise rotator for me would be the Yeasu G450. Mains, runs happily off a cheapo inverter, a decent turn of speed, not toooooo heavy for a /p mast top and generally available on the 2nd hand market. Others will comment I am sure....

The other more "enterprising" method could be a powerful 12v stepper motor, an Arduino and some code. That kind of design could wipe out other entries at next year's Construction Competition!  For /p you might not need a display as you can SEE your beam direction. Another idea to gather practical comments perhaps ...

73 and "Merry Christmas to all... and to all a Good Night's DX"

ACM




Dom - 2E0WHQ
 

There you go John,

That's two of us who have mentioned the Big Wheel antenna. I mentioned it in my post too. They are marketed by Wimo.

https://www.wimo.com/en/big-wheel-2m

73

Dom, 2E0WHQ


John Claridge 2E0JJC
 

My apologies Dom. I missed seeing it in your email. My error has reminded me to check if my eye cataract is "ripe" enough yet for the eye surgeon.

John

On Sat, 1 Jan 2022, 1:53 pm Dom (2E0WHQ), <domwilko@...> wrote:
There you go John,

That's two of us who have mentioned the Big Wheel antenna. I mentioned it in my post too. They are marketed by Wimo.

https://www.wimo.com/en/big-wheel-2m

73

Dom, 2E0WHQ