RE: LF: XPQ WSPR15 475/136

[Markus Vester <markusvester@aol.com>]

Hi Laurence,

 

thanks for the detailed info! Looks like you're set up pretty well to make use of whatever little straw of propagation you can cling to ;-)

Reason I asked was that I'd been contemplating a 137 / 475 k diplexer for my vertical. But after doing the analysis I gave up on it as the compromises regarding losses, bandwidth and voltages just seemed unacceptable.

 

So good luck and have a nice weekend,

 

Markus (DF6NM)

 

PS it looks like all your mails are getting through blacksheep.  But you may not be getting them back yourself. I've been experiencing that effect now and then, and always found it pretty confusing.

 

-----Ursprüngliche Mitteilung----- 
Von: Laurence KL7 L <hellozerohellozero@hotmail.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 24 Okt 2015 7:04 pm
Betreff: RE: LF: XPQ WSPR15 475/136

Morning Markus - well the transmitters held up well and no issues. The two transmitters and  tx antennae are independent of each other. 475 is a 70ft vertical large top loaded Marconi with 250ft-ish top. The 136kHz is the  standard "Bill" 550ft circumference loop with 60/70ft vertical sections at each end with about 50A loop current. The only difference this year is the 136kHz loops orientation which is now 092/272degT which does not favor Eu (in theory!), and at the moment is a single conductor so a little more lossy - I have physical tree dead and active load  limits here - a bit more flimsy branches than Oklahoma, even so Im effectively "guying" a few of the trees with the antennae wire having around 1200 pound break strain :-)

Both are in the middle of the Boreal forest (100m LMR400 coax runs) which has its issues but for 136kHz its really the only solution that works where I can run a reasonable amount of power and not worry too much about setting it alight,  given the relatively lower voltages on the loop.

475 is a U3 driving the W1VD 500W PA and 136 is a U2 driving the Decca 5501 on two of three modules with 58V both with their own GPS drivers.

Due to construction and tight thermal case the U3 has a little more "drift" during the 15 min tx periods but is tolerable.

  I can still run other tx sources to either PA so will be playing with other modes during winter - Id like to do some of this coherent stuff as I have a reasonable source with the HP3336b/gps available but thats going to take me a search in my cable box for the  serial keying stuff  from a few years back.

Conditions are still "cooling off" iono wise from the recent sol/geomag stuff...and its still physicallt warm here temp wise in Alaska so environmental losses are still higher because of it. I need to build a second Jim M0BMU visual phase/power meter and Ive just love having one of those in line...

Laurence KL7 L WE2XPQ (jet lagged so sorry for typos) 

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To: rsgb_lf_group@blacksheep.org
From: markusvester@aol.com
Date: Sat, 24 Oct 2015 04:37:16 -0400
Subject: Re: LF: XPQ WSPR15 475/136

Hi Laurence,

 

interesting... are you transmitting into a single dual-resonant antenna?

Best 73,

Markus

 

-----Ursprüngliche Mitteilung-----
Von: Laurence KL7 L <hellozerohellozero@hotmail.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 24 Okt 2015 5:20 am
Betreff: LF: XPQ WSPR15 475/136

Ill give this a go but will run parallel 136 and 475kHz WSPR15 tonight  - 800W on 136 and 200W on 475 all being well - they are forecasting a little geomag so will shall see. Light dim in the shack a bit....

Ill be off around 0900 to look for SAQ on 17.2kHz

Laurence KL7 L WE2XPQ