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 <grants2 at 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
>>
>>
>