Re: LF: On air again in LF WSPR-15

[DK7FC <selberdenken@posteo.de>]

Hi Luis,

thanks for the nice readably summary report.
Oh yes it was an impressing night and good resultsfor us. I saw you were decoded at SM2DJK which is a good distance, and R7NT was seen at 2E0ILY. There are more challenges like the path from EB8ARZ to SM2DJK, that would be about 4000 km and still inside the continent.
I also thought about LU8YD but also about PY2PLL.
EB8ARZ has the perfect RX location, so if LU8YD would transmit on LF, like in the past, it could work in WSPR-15 just before the sunrise in EA8.

About the MOSFET discussion, i'm using IRFP460A types in H bridge configurations from SLF to MF, i.e. the full spectrum :-) Bridge voltage is 320 V DC, the rectified mains voltage.
With the currently pair (4 pcs) of FETs i'm TXing since hundreds of hours on LF without problems. They are of course in TO-247 design and cost just 2.2 EUR, so a BANG/year wouldn't really hurt.

73, Stefan



Am 21.11.2018 10:25, schrieb VIGILANT Luis Fernández:

Hi LF

 

After some time of forced QRT I’m again on air transmitting LF WSPR-15

 

Tried a first transmission in WSPR-2 yesterday at 19:30 and all the rest were WSPR-15 at minute 15 and 45

Found a “safe” combination of PA power for the 15min Tx. Need to modify the PA providing

proper cooling. Anyway last night could work at 1600mA RF using a 16V@10A power supply

 

Got many spots from Paul, N1BUG but noting from Russia side. Completely different from Stefan

which got a single decode from Paul, eleven decodes from Ruben EB8ARZ  and many from four Russian stations

 

I’m in contact with Alex, LU8YD to setup his Rx in WSPR-15 using WSJT-X and the modifications

mentioned in this reflector. May be we can get some sourprises from South Amercia in LF. Worth a try

 

Talking about transistors, I purchased a pair of little beasts. This are TO-247 devices

rated 1Kw max dissipation and 500V 60A 0.1Ohm Rds. And the price is not so high for low quantities

€6.90 at Farnell for less than 5 pieces

 

It does not mean you can squeeze them to 1Kw but for a G0MRF classD PA they always run safely

so will last long and hopefully worth the purchase. For those interested, the device is made by IXYS

  IXFH60N50P3

 

About WSPR-15 notification to SWLs I added a post to the WSPRNET forum

http://wsprnet.org/drupal/node/7891

 

Some of the posts can be seen in the initial page at http://wsprnet.org/drupal/  but seems that they are selected manually by

administrators, so there can be some delay to see it in first page. Hope they can spread the news, because there are still many

SWLs using WSPR-2 only in LF, specially in north America. Would be also interesting to get the US Tx stations in WSPR-15 too

That would speed up transition. This is a RARE event this days, updating to an “old” mode. May be Microsoft take note of it and be

back to Win7  ;-)

 

73 de Luis

EA5DOM