Topband
[Top] [All Lists]

Re: Topband: AS / EU QRM - The Cocktail Party Effect

To: David Olean <k1whs@metrocast.net>
Subject: Re: Topband: AS / EU QRM - The Cocktail Party Effect
From: Richard McLachlan <richard@rodsley.net>
Date: Mon, 25 Nov 2019 19:34:20 +0000
List-post: <mailto:topband@contesting.com>
The QRM levels here in EU are only really a big problem during contests. In 
early evening our time (1600-2000 UTC) there are a lot of Eastern Europeans on 
but as the band is not yet open to the West that is not a problem. I tend not 
to operate from around 2200 to 0500 but if I get up early 160 is really quiet 
between 0530 UTC and dawn at 0700ish. I can then typically only hear a few USA 
stalwarts on the band with no QRM whatsoever.

73
Richard
G3OQT

> On 25 Nov 2019, at 19:13, David Olean <k1whs@metrocast.net> wrote:
> 
> OK I guess the problem is QRM levels in EU.  The CQ WW weekend is a big 
> difference from a typical Wednesday or Thursday evening. I was just getting 
> paranoid when many stations in a row could not copy me while I was hearing 
> them with great signals and 559 to 589.  I am thinking that maybe my Europe 
> beverage is working very well. It is long at about 1100-1200 ft (350M) and 
> consists of two sets of wires spaced 400 ft apart. (120M)  We had terrific 
> winds on Friday night and I was not QRV but wondered if any trees had fallen 
> in the woods due to the high winds. I had just fixed all my receive wires two 
> weeks ago. I walked along my beverage wires today, and found a huge tree had 
> fallen across my South beverage and broken the wire. It also ripped the 
> termination off the far end.  Next I found another tree that managed to fall 
> across both the South beverage as well as one of my Europe beverages. I had 
> to get the chainsaw out and now I have a full pickup truck load of firewood 
> and the two an
 tennas are working well again. I also had a tree across the JA beverage.  My 
East, Southwest, and West wires all were OK. There are a few more I have not 
gotten to yet. Maintaining wires in the woods is never ending!
> 
> On Saturday night, I saw no problem with the EU wires or the JA wire (It 
> works well towards Hawaii and CA) even though they had problems. I did sense 
> that my South wire was not so hot. No wonder, it was broken in half and 
> laying on the ground with no termination on the southern end.  The EU wire 
> seemed OK to me even with a tree across it. Same with the JA wire.  Oh well, 
> at least I got some firewood out of the deal.
> 
> 73
> 
> Dave K1WHS
> 
>> On 11/25/2019 3:08 PM, Fred Kleber wrote:
>> 
>> Hi Top Banders,
>> Having operated from the other end on a number of continents, I offer the 
>> following explanations of why NA hams may wonder why they can't work distant 
>> stations:
>> SE Asia - The amount of non-ham QRM in the ham bands is unbelievable.  Most 
>> notable are the Indonesian (and probably other countries) fisherman who 
>> populate wide swaths of spectrum and have little to no regard for spectrum 
>> allocations.  They just go buy a cheap ham rig, make it general coverage, 
>> and off they go.  Additionally the beacons on fishing nets can also create 
>> quite a racket.  Oh yes, the commercial power suppliers in poorer countries 
>> most likely don't even care about repairing line nose.  One other challenge 
>> is the echo from NA stations which is frequently present on the low bands.  
>> Pileups particularly exacerbate this phenomenon.
>> Europe - Here's the cocktail party analogy.  When a cocktail party starts, a 
>> few people come in the door, grab a drink and start talking to each other.  
>> As more people join the party, the room fills up and the ambient noise (QRM) 
>> rises.  In order to be communicate, guests talk louder.  More people join 
>> the party and the audible QRM noise floor rises.  In the radio world 
>> parallel, equate guest's speech with RF and talking louder with running more 
>> power.  Then consider that many countries don't effectively regulate TX 
>> power output, and you have a real mess.  Most north american's can't 
>> understand when I tell them that if you're not at least S-9 on 80-20 meters, 
>> you're most likely not going to be heard.
>> I hope you find this information useful.
>> 73 & good DX,Fred, NP2X / K9VV et al.
>> _________________
>> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector

_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector

<Prev in Thread] Current Thread [Next in Thread>