True, but typically I was always taught that you don't take ground effects
into consideration when computing counterpoise lengths for ground. I always
used 246/Freq in MHz. But, you're only talking an inch difference, max.
----- Original Message -----
From: "Butch Bussen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, August 17, 2013 5:59 PM
Subject: Re: 2-meter Antenna Challenge
> not true for antennas. You have to count in what is called end effect.
> formula for a half wave is 468 and a quarter wave 234 over freq in mhz.
> Only time you use the 300 for meters or 984 for feet is if you are
> calculating tuning stubs and such, then you would also multiply by the
> volocity factor of the coax.
> On Sat, 17 Aug 2013, Steve wrote:
>
>> ABout 20.2 inches is a quarter wave. Wevelength = 300/Freq in megahertz
>> 300/146. Then divide that result by 1/4 to get your quarter wavelength
>> counterpoise.
>>
>> Steve, K8SP
>> ----- Original Message -----
>> From: "Tom Behler" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Saturday, August 17, 2013 4:00 PM
>> Subject: Re: 2-meter Antenna Challenge
>>
>>
>>> Mark:
>>>
>>> So, now I'm thinking of two things here.
>>>
>>> First, the magmount I have is sealed, so I'm not sure how I would get to
>>> the
>>> shield of the coax to make the connection you describe.
>>>
>>> Also, I'm doing some mental calculations as to the length of the
>>> counterpoise.
>>>
>>> Can someone refresh me as to the formula you would use for that, keeping
>>> in
>>> mind that I'd like the antenna to perform best around 146
>>> megahertz--pretty
>>> much in the center of the band.
>>>
>>> Tom Behler: KB8TYJ
>>>
>>> ----- Original Message -----
>>> From: "Mark WZ0K" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Saturday, August 17, 2013 2:45 PM
>>> Subject: Re: 2-meter Antenna Challenge
>>>
>>>
>>>> Hi Tom,
>>>> On The antenna situation. Some years ago, I had a 5/8 wave mag
>>>> mount
>>>> that I used in a window sill. It performed well enough. However, After
>>>> hearing about using a counterpoise, I loosened the antenna from the mag
>>>> mount and slid a thin piece of wire between the antenna and the mag
>>>> mount.
>>>> I
>>>> made sure it touched the metal part of the bracket that was connected
>>>> to
>>>> the
>>>> braid of the coax. The wire was cut to a quarter wave. Suddenly my
>>>> reports
>>>> were better in all the repeaters, and I started reaching in to machines
>>>> that
>>>> I could not reach before. I hope this helps.
>>>>
>>>> God bless,
>>>> Mark
>>>> God loves You!
>>>> My personal website: Http://www.christiantraditions.info
>>>> The Blind Computer People List:
>>>> http://christiantraditions.info/mailman/listinfo/blindcomputerpeople_christiantraditions.info
>>>> Follow me on Twitter: https://twitter.com/TorgersonMark?refsrc=email
>>>> -----Original Message-----
>>>> From: [log in to unmask]
>>>> Sent: Saturday, August 17, 2013 11:32 AM
>>>> To: [log in to unmask]
>>>> Subject: Re: 2-meter Antenna Challenge
>>>>
>>>> Two suggestions:
>>>>
>>>>
>>>>
>>>>
>>>>> Hi, all.
>>>>>
>>>>> I hope I am not wearing out my welcome back to the list, but I have a
>>>>> challenging antenna situation I'm currently facing in the new faculty
>>>>> office
>>>>> I will be occupying starting this Spring semester.
>>>>>
>>>>> I currently have an old Kenwood TMV7A in the office, with which I have
>>>>> always had at least some luck, in terms of getting into our local
>>>>> 2-meter
>>>>> repeater. The repeater is about 15 miles from the University.
>>>>>
>>>>> However, in my new office, I am finding that the small mag-mount
>>>>> antenna
>>>>> I
>>>>> have always used simply does not allow me to reach the repeater
>>>>> consistently. Currently, I have the magmount sitting on a small metal
>>>>> bracket on the window sill in the office. It is right next to the
>>>>> window,
>>>>> so I would think that should help. However, I do not have much of a
>>>>> ground
>>>>> plain for the magmount. I also think there is some de-sensing going
>>>>> on
>>>>> with
>>>>> the steel of the office building, and with other surrounding computer
>>>>> equipment in the office complex.
>>>>>
>>>>> I do have a filing cabinet on the other side of the office that I
>>>>> could
>>>>> use
>>>>> as a ground plane, but the top of the filing cabinet is too high, and
>>>>> there
>>>>> is not enough space between it and the office ceiling to accommodate
>>>>> the
>>>>> magmount antenna.
>>>>>
>>>>> This obviously is a very challenging situation, and I also have to be
>>>>> at
>>>>> least somewhat concerned with appearance, in terms of not having an
>>>>> ugly-looking antenna that might draw more attention to what I am
>>>>> trying
>>>>> to
>>>>> do than I might want.
>>>>>
>>>>> Do any of you have any suggestions as to how to help the mag-mount
>>>>> perform
>>>>> better in this situation?
>>>>>
>>>>> Or, might I be better off considering another type of antenna, such as
>>>>> a
>>>>> J-pole of some sort.
>>>>>
>>>>> I would appreciate any thoughts.
>>>>>
>>>>> Tom Behler: KB8TYJ
>>>>>
>>>>>
>>>>
>>
>>
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