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)
To:
[email protected]From:
[email protected]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 <
[email protected]>
An: rsgb_lf_group <
[email protected]>
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
