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Messages - syfr

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121
Equipment / Re: Interesting Chinesium SI4732 Shortwave/Air/FM
« on: May 20, 2021, 1929 UTC »
Hey, if it works, and is reliable, it's all great once you button up the case.   It looks good to me.

Hopefully that'll serve to lower some of the noise on the 5V rail. Nice work!

122
Equipment / Re: T2FD results (58 ft)
« on: May 20, 2021, 1925 UTC »
Later that week....


I discovered that I had neglected to connect the terminating resistor! 

Down came the antenna and it's back up again with the termination .  I'm quite pleased with the antenna, though I'm getting slammed by interference from a local (1- 2 miles away) AM station on 1090 which creates mixing products across the spectrum . Even with that, the T2 is quite good.   I'll look forward to writing it out tonight.  I don't have a suitable enclosure for the balun yet, so there's a pretty big mismatch at the feedpoint still.

It's kind of interesting to connect to Chris's Kiwi with the 58 ft T2 and mine , and tune to the same station. There's a very noticeable diversity receiver effect as we're about 120-140 miles apart I'd guess.   If you offset the tuning (on CW especially) by 100 hz or so the effect is really cool.

Feel free to try :   mykiwisdr.hopto.org:8073 or 8074.       It'll be gone during thunderstorms but generally back on ASAP. 


123
Equipment / Re: RF return issue
« on: May 18, 2021, 1324 UTC »
Have you tried transmitting into a dummy load just to isolate the potential cause? 

124
Equipment / Re: T2FD results (58 ft)
« on: May 17, 2021, 2238 UTC »
Thanks Chris.  The impedance transformation makes for higher efficiency power transfer, so I get that.   When I replace the "haul line"  I'll put the balun in place and see what happens.  I suppose that the impedance of the antenna as it varies over frequency is swamped by the 900 ohm resistor and I should choose a squid tap close to that?

I'm hoping I stayed clear of the poison ivy patch I discovered back there.  After getting the antenna up I went full Agent Orange on that area.




125
Equipment / Re: Interesting Chinesium SI4732 Shortwave/Air/FM
« on: May 17, 2021, 2232 UTC »
Thanks for the good info. I can use the IDE ok, and I'm good at following the bouncing ball instruction-wise, but it doesn't take much to happen to put me out into the weeds.  I'm one of those eternally grateful for installation packages.

Yeah, there's not a lot of extra headroom in a Nano, so it's cool they got a decoder packed in there. I've never seen one work very well under real world conditions, but it's fun to play with them.

Cool toy for small bucks it seems like.

126
Equipment / Re: Interesting Chinesium SI4732 Shortwave/Air/FM
« on: May 17, 2021, 1939 UTC »
That's cool, and a lot of changes. Are they managing the changes through Git or something similar?

I'm pretty sure you must be better at working with downloading/building firmware than I am .   :-)

127
Equipment / Re: Lab599 Discovery TX-500? Yeah, I want one!
« on: May 17, 2021, 1936 UTC »
How does he / she like it?   I'll have to go hunt for a review.

128
Equipment / Re: T2FD results (58 ft)
« on: May 17, 2021, 1934 UTC »
I have one of Chris's baluns, but forgot to install it when I hoisted up the antenna.   :-)

It's just a temporary rig as it is.  I wonder if there'll be a noticeable diff with the balun?

129
Equipment / T2FD results (58 ft)
« on: May 17, 2021, 1707 UTC »
Thanks to Chris, I built a 58 ft T2FD and got it hung in the back yard in test.   The high end is up at about 48 ft  with the antenna sloping at about 25 degrees with the low end up about 5 ft.  The antenna is at the end of about 175 ft of 52 ohm coax heading to my Kiwis though a homebrew active splitter.  I used a 900 ohm resistor and there's currently no balun.

Chris and I are only 120 miles apart or so, and it's interesting to compare results in our installations. While I'm super impressed with Chris's 120 ft T2, I'm not sure I could actually get that installed by myself.

My reference antenna (one that I left hooked up all the time to the Kiwis) was a trap dipole in the attic (30' up) that was only so so, and prone to lots of noise being emitted by all the junk in the house. 

There's some "industrialization" that needs to happen to keep this thing in the air, but I'm impressed so far.  S/N is MUCH improved over the noisy attic antenna.  I'm looking forward to the nighttime results on 40M as my benchmark.

Thanks to Chris for the inspiration.

130
HF Beacons / Re: Mid Atlantic Beacon Loggings
« on: May 17, 2021, 1149 UTC »
14 May 2021:
1013 UTC: Good signals from both Windy and the DW. This was using my newly built (but not yet finished) 10 ft diameter resonant loop antenna. Better reception than the sky loop. So we're moving in the right direction.

Details man, DETAILS! :-)


131
Equipment / Re: Lab599 Discovery TX-500? Yeah, I want one!
« on: May 17, 2021, 1146 UTC »
Now that does look interesting!

Still looks like vaporware at the moment, but there's hope. The Rx efficiency is impressive (100mA)

132
Chris, do you use a pulley in the trees, or just pull up (and down) on a plain rope?

133
2 element inverted vee array?

134
Equipment / Re: RETRO RECEIVER REVIEW #14 - The MURPHY B40
« on: May 17, 2021, 0005 UTC »
I always thought these were one of the coolest looking old radios ever. What a great rig. 100 lbs... no problem, that's what a proper shortwave should weigh :-)

This looks like some art deco office building.

135
Equipment / Re: Interesting Chinesium SI4732 Shortwave/Air/FM
« on: May 17, 2021, 0000 UTC »
I'll be watching your progress.  A software "kit" is a good way to look at it.   

Please keep posting what you find, it's much appreciated.

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