Re: Topband: Radials question

[Mike Paskeuric]

Re: Topband: Radials question

Hey Gang,

  Thank you for the comments and I been re-reading them and learning.
This will be a fun late summer or early fall project.
Thanks!
Mike
n0 odk
73


On Tue, Jun 13, 2017 at 9:54 AM, Grant Saviers <gran...@pacbell.net> wrote:

> The larger the diameter of the antenna, the broader the bandwidth. So an
> aluminum self supporting vertical that starts with 3" diameter tubing (the
> HD DXE starts with 4")  can have twice the intrinsic bandwidth of 16ga
> wire.  It also gets a bit shorter for same resonance frequency.  I had a
> guyed 80m vertical of 3" irrigation tubing which had about double the
> bandwidth of a wire one.
>
> Another choice is a simple fixed series capacitor with a shorting relay to
> move the resonance up the band.  I use 3 series caps and paralleled relays
> on my 160m T to cover all of 160 in 50KHz steps, <2:1.  It worked out that
> the short, C, C/2, C/3 series values were right on to cover the band in
> even steps. The untuned resonance is 1810KHz.  Others use series variable
> capacitors, but a vacuum variable is probably needed at the smallest value
> of C.  That costs a lot more than fixed 1KV caps and takes longer to QSY.
>
> Grant KZ1W
>
>
> On 6/12/2017 20:29 PM, Mike Paskeuric wrote:
>
>> Hey Topbanders,
>>
>>I was looking to buy or make a mono type 80 meter antenna for DXing.
>>
>> I was wondering couple things. If I make a full quarter wave vertical WIRE
>> in tree 65 feet tall and see DX Engineering verticals claim 65 foot tall
>> but wider bandwidth. What is their secret or just advertisement?
>>
>>Second question, I understand more radials make vertical better, but
>> what
>> happens if one side half or one third the length radials due to space in
>> yard are shorter by 20 to 30 foot? Is it noticeable enough to buy a
>> vertical in middle of yard instead of wire in tree towards side of yard?
>> Dollars verses radial lengths.
>>
>>Third and last question, can some of the radials, quarter of them,
>> overlap with radials of another antenna (160M mono vertical Gladiator
>> antenna)? Would it affect the performance noticeable.
>>
>>I don't need long answers, just something to help out a bit.
>> Not sure what antenna to buy or make yet. I am in 2 and half acres and can
>> maybe stretch in field next to me some with no one knowing. Not many 80M
>> momo antennas to choose from.
>>It is a late Summer or Fall project so time to think.
>>
>> Mike
>> n0 odk
>> 73
>> thanks for suggestions gang.
>> _
>> Topband Reflector Archives - http://www.contesting.com/_topband
>>
>>
>
_
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Re: Topband: Radials question

[Grant Saviers]

The larger the diameter of the antenna, the broader the bandwidth. So an 
aluminum self supporting vertical that starts with 3" diameter tubing 
(the HD DXE starts with 4")  can have twice the intrinsic bandwidth of 
16ga wire.  It also gets a bit shorter for same resonance frequency.  I 
had a guyed 80m vertical of 3" irrigation tubing which had about double 
the bandwidth of a wire one.


Another choice is a simple fixed series capacitor with a shorting relay 
to move the resonance up the band.  I use 3 series caps and paralleled 
relays on my 160m T to cover all of 160 in 50KHz steps, <2:1.  It worked 
out that the short, C, C/2, C/3 series values were right on to cover the 
band in even steps. The untuned resonance is 1810KHz.  Others use series 
variable capacitors, but a vacuum variable is probably needed at the 
smallest value of C.  That costs a lot more than fixed 1KV caps and 
takes longer to QSY.


Grant KZ1W


On 6/12/2017 20:29 PM, Mike Paskeuric wrote:

Hey Topbanders,

   I was looking to buy or make a mono type 80 meter antenna for DXing.

I was wondering couple things. If I make a full quarter wave vertical WIRE
in tree 65 feet tall and see DX Engineering verticals claim 65 foot tall
but wider bandwidth. What is their secret or just advertisement?

   Second question, I understand more radials make vertical better, but what
happens if one side half or one third the length radials due to space in
yard are shorter by 20 to 30 foot? Is it noticeable enough to buy a
vertical in middle of yard instead of wire in tree towards side of yard?
Dollars verses radial lengths.

   Third and last question, can some of the radials, quarter of them,
overlap with radials of another antenna (160M mono vertical Gladiator
antenna)? Would it affect the performance noticeable.

   I don't need long answers, just something to help out a bit.
Not sure what antenna to buy or make yet. I am in 2 and half acres and can
maybe stretch in field next to me some with no one knowing. Not many 80M
momo antennas to choose from.
   It is a late Summer or Fall project so time to think.

Mike
n0 odk
73
thanks for suggestions gang.
_
Topband Reflector Archives - http://www.contesting.com/_topband



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Re: Topband: Radials question

[k8gg]

Hi Mike, et al,

Here are my thoughts interlaced.


> Hey Topbanders,
>
>   I was looking to buy or make a mono type 80 meter antenna for DXing.
>
> I was wondering couple things. If I make a full quarter wave vertical WIRE
> in tree 65 feet tall and see DX Engineering verticals claim 65 foot tall
> but wider bandwidth. What is their secret or just advertisement?

***Using a wire - say 12 gauge - Will probably give you a 100 kHz 2:1 SWR
bandwidth.  Using a vertical say 2" O.D. at the bottom and 1.25" O.D. at
the top will generally triple the bandwidth.  Make a model with EZNEC (r)
and see what you get.  Ground losses also increase band width of these
antennas, since "Rg" is in series with the actual antenna impedance.

>
>   Second question, I understand more radials make vertical better, but
> what
> happens if one side half or one third the length radials due to space in
> yard are shorter by 20 to 30 foot? Is it noticeable enough to buy a
> vertical in middle of yard instead of wire in tree towards side of yard?
> Dollars verses radial lengths.

***It does not make a lot of difference.  One K1 has a 160 vertical near
his house and most of the radials are over 180 degrees.  What is important
is to get enough radials on/in the ground.

>
>   Third and last question, can some of the radials, quarter of them,
> overlap with radials of another antenna (160M mono vertical Gladiator
> antenna)? Would it affect the performance noticeable.

###In my opinion, if the ground radials are below "elevated radials" for
another antenna there should be no problem.   The reverse is also true.  I
know a ham with 80 meter 4-square around a 160 meter vertical.  The 80
meter radials are elevated and the 160 meter radials are in the sod.

>
>   I don't need long answers, just something to help out a bit.
> Not sure what antenna to buy or make yet. I am in 2 and half acres and can
> maybe stretch in field next to me some with no one knowing. Not many 80M
> momo antennas to choose from.
>   It is a late Summer or Fall project so time to think.
>
> Mike
> n0 odk
> 73
> thanks for suggestions gang.
> _
> Topband Reflector Archives - http://www.contesting.com/_topband

***Good luck  de George,  K8GG

_
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Re: Topband: Radials question

[Tim Shoppa]

Mike, a different question than you asked, but if you have two trees or other 
supports at 65 feet or greater and more than 130ft apart, I think an 80M dipole 
strung between them will be a better all around antenna than a vertical. If you 
can get to 80ft or 100ft the dipole was be markedly better. If you only have a 
single support an inverted V will be almost as good.

This same antenna, you can tie the feed line together at ground level and feed 
as a Marconi T against ground on 160M.

Back to your original questions:

As to differing bandwidth claims, they must be using slightly different 
standards for bandwidth.

As long as you have more than a couple radials, I would not worry at all about 
an asymmetrical radial field. Put down as much copper in whatever directions 
you got. It's the guys with only 1 or 2 radials that have to worry about tuning.

Tim N3QE

> On Jun 12, 2017, at 11:29 PM, Mike Paskeuric  wrote:
> 
> Hey Topbanders,
> 
>  I was looking to buy or make a mono type 80 meter antenna for DXing.
> 
> I was wondering couple things. If I make a full quarter wave vertical WIRE
> in tree 65 feet tall and see DX Engineering verticals claim 65 foot tall
> but wider bandwidth. What is their secret or just advertisement?
> 
>  Second question, I understand more radials make vertical better, but what
> happens if one side half or one third the length radials due to space in
> yard are shorter by 20 to 30 foot? Is it noticeable enough to buy a
> vertical in middle of yard instead of wire in tree towards side of yard?
> Dollars verses radial lengths.
> 
>  Third and last question, can some of the radials, quarter of them,
> overlap with radials of another antenna (160M mono vertical Gladiator
> antenna)? Would it affect the performance noticeable.
> 
>  I don't need long answers, just something to help out a bit.
> Not sure what antenna to buy or make yet. I am in 2 and half acres and can
> maybe stretch in field next to me some with no one knowing. Not many 80M
> momo antennas to choose from.
>  It is a late Summer or Fall project so time to think.
> 
> Mike
> n0 odk
> 73
> thanks for suggestions gang.
> _
> Topband Reflector Archives - http://www.contesting.com/_topband
_
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Re: Topband: Radials question

[Mike Paskeuric]

I mis-wrote for tired right now. The 160M Gladiator is not top loaded, it
has 4 raised radials with traps. Works great tho for me. It helped me get
two Hawaii and one Alaska for WAS and 14 DXCC in one night. Not much know
about Gladiator tho it is 1.1 antler high.

 I ment the 40M mono radials it might cross on the 80 meter radials, not
the 160M antenna. Sorry, going to bed soon. Should have known my set up.
Mike
73
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