[Lowfer] Wm beacon testing tonight @ JAY
jrusgrove at comcast.net
jrusgrove at comcast.net
Tue Nov 18 17:23:09 EST 2014
Charlie
Haven't looked into conductor size for verticals. I'm sure my 90' vertical height Marconi would do
better with a cage instead of the #12 THHN I'm currently using.
Litz that size is certainly available new but one would pay dearly for it. I picked up several
hundred feet a few years back from the LF guys in G land. The radio club dismantled a number of
Decca coils with the Litz proceeds going to support the club. Very nice stuff but still not cheap.
It's destined for a 137 kHz loading coil ... someday.
Every dB in 'lowferdom' counts way more than a dB at HF ... that's for sure. Look forward to seeing
your beacon again this winter!
Jay
----- Original Message -----
From: "Charlie , W5COV" <cvest at cox.net>
To: <lowfer at mailman.qth.net>
Sent: Tuesday, November 18, 2014 4:36 PM
Subject: Re: [Lowfer] Wm beacon testing tonight @ JAY
> Jay,
>
> Just curious if you have run similar tests on conductors for say a nominally 50 foot vertical ?
>
> Also is 1/4" Litz available commercially ? I know it would be expensive, but most of us didn't get
> into this hobby because it was cheap. <grin>
>
> Just curious if it was commercially available, or if perhaps someone had built their own version
> of a Litz type wire conductor. Part 15, even one additional dB can make all of the difference in
> the world of being seen or not.
>
> Although I know one can get on the air these days with a fairly decent regular ham station by
> building or even buying some older gear for under $100.
>
> Thanks,
>
> Charlie, W5COV
>
> On 11/18/2014 12:56 PM, N8OOU wrote:
>> Jay, Thanks for the operating info gathered from your previous tests. I will take it into
>> consideration in my future builds. I don't consider your input a wet blanket, as I have no
>> mileposts to judge forward or backward progress.
>>
>> Implementing a large transmitting loop here is well within reason, but other less controversial
>> designs can easily be accommodated too. I want the station to operate as close as possible to
>> the level of it's previous operator, but it must do so within my comfort level. That's a major
>> component in the beacon testing I am doing now.
>>
>>
>> 73 de N8OOU - Mike Meek
>>
>> On 11/18/2014 09:56 AM, jrusgrove at comcast.net wrote:
>>> Mike
>>>
>>> Dug out my antenna notes on lowfer VD from many years ago. The antenna
>>> was 200' perimeter. The loop conductor was milspec RG-11 (excellent
>>> braid) using the outer braid as the loop conductor. Since the antenna
>>> could be raised and lowered with relative ease I also made measurements
>>> on 200' perimeter loops made from #12 and #8 copper wire to see how they
>>> performed. Analysis was based on measured antenna current which gives an
>>> accurate indication of antenna Rtotal. The Rtotals can then be compared
>>> to predict the dB difference between the antenna conductors. I also made
>>> some calculations based on other antenna conductors. RG-11 is the
>>> reference conductor at 0 dB.
>>>
>>> 1/4" Litz......................+1.3 dB
>>> 7/8" Heliax.................+ 0.9 dB
>>> 1/2" Copper tubing.....+0.4 dB
>>> RG-11............................0 dB
>>> #8 Copper.................-2.4 dB
>>> #12 Copper...............-3.8 dB
>>>
>>> You're #16 loop conductor is going to be even further down the list ...
>>> that plus the fact your antenna area is less than that of a 200'
>>> perimeter are going to make this a challenge. Keep in mind that on an
>>> Argo display a 1 dB difference in received signal level can mean the
>>> difference between barely visible and solid white line reception. Not
>>> trying to throw a wet blanket on your efforts ... just giving you an
>>> idea what to expect and what's possible.
>>>
>>> Jay W1VD WD2XNS WE2XGR/2
>>>
>>>
>>>
>> ***************** snip ***********************
>> ______________________________________________________________
>> Lowfer mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/lowfer
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Lowfer at mailman.qth.net
>> Post must be less than 50KB total for message plus attachment!
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
>
> ---
> This email is free from viruses and malware because avast! Antivirus protection is active.
> http://www.avast.com
>
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
> Post must be less than 50KB total for message plus attachment!
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
More information about the Lowfer
mailing list