HFU HF Underground
Loggings => MW Loggings => Topic started by: pinto vortando on March 02, 2019, 0323 UTC
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AM BCB conditions have been rather unsettled here in Michigan the past couple of evenings but
anyway got out my xtal set last evening around 2100 EST.
As expected, results were not too good... lots of QSB. However, did manage to
positively ID several stations as they faded in and out:
WHAM-AM 1180 Rochester NY
faded in just enough to get the ID, "Wham news radio 11-80"
then gone
KDKA-AM 1020 Pittsburg PA
talking about the Pittsburg Home and Garden Show
WLW-AM 700 Cincinnati OH
could hear it in and out under local powerhouse WJR 760
(remember this is a xtal set, selectivity isn't the greatest)
WBZ-AM 1030 Boston MA
"Nightside" program with host Dan Rea
this station, unlike the others, had a solid signal in here all evening
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What's your circuit?
Ill try over a few nights. This one I used a 386 chip op amp , the slight hum in the video is from wall wart ps which can be eliminated with a 9 volt battery but it rips through them. You can get decent selectivity by adding a trap or tuning the antenna coil and it also allows a longer antenna without overloading.
. The sensitivity is limited by the diode , not all are the same.
https://m.youtube.com/watch?v=1K4KB55-QBw
Over a few nights clipped on to the hf wire
WPTY 1690 Lexinton Pk MD Lionel Ritchie
WBCN 1660 Charlotte NC sports discussion
? 1590
? 1570
WFME 1560 NY NY
WGH 1310 local
WTJZ 1270 Newport News Va
WWVA 1170 Wheeling WVa
KYW 1060 Philadelphia newsradio
WVXX 1050 Local " La Selectra" " los top 20"
WBZ 1030 Boston
WINS 1010 NY NY
UNID 960 Political talk
WCBS 880 NY NY
WTAR 850 local swamping adjacent
WNIS 790 local swamping adjecent
CFZM 740 Toronto Rick Springfield Jessie's girl good copy
WOR 710 New York " WOR news time 905"
WGN 720 Chicago
WFAN 660 New York NY. Sports excellent copy
WSNR 620 Lyndhurst NJ
WCAO 600 Baltimore gospel
RR 570 Santa Clara time blips
CW on 160 meters even though the trap doesn't reach that high
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1n5711 and bat46 are tops for silicon diodes, try a 1n34a for "geranium" diodes, better than a 1n60.
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I bought a 10 pack of 1n34 and checked through. Some are noticeably louder than others.
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What's your circuit?
Ill try over a few nights. This one I used a 386 chip op amp , the slight hum in the video is from wall wart ps which can be eliminated with a 9 volt battery but it rips through them. You can get decent selectivity by adding a trap or tuning the antenna coil and it also allows a longer antenna without overloading.
. The sensitivity is limited by the diode , not all are the same.
Circuit is just typical basic diode and with 250 uH coil and 365 uuf air variable condenser.
Not all diodes are created equal as you noticed. Had some old (50+ yrs) germanium
type, probably 1N34, here and picked the hottest of the bunch to use in the set.
Supposedly the old stock stuff is hotter than new ones... idk ???
The key is an antenna tuning unit inductively coupled to the tuning coil in the set.
The antenna coil is tuned by a couple of 365 uuf condensers in a switchable
series-parallel arrangement. The trick is getting the proper spacing when coupling
the tuner to the set. The closer the better for sensitivity but too close and selectivity
becomes bad to the point where stations are heard randomly all over the dial (no linear
"tracking" so to speak).
Have found that spider web wound coils seem to perform better than the usual
cylinder wound coils.
btw, you may want to try running the op amp on 12 volts (say a couple of 6 volt
lantern batteries in series or a sealed 12 volt VRLA battery, the VRLA could be recharged if
you have the proper means to do so), should run a looong time. :)
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A tunable loop should do well in enhancing selectivity.
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A tunable loop should do well in enhancing selectivity.
Never tried that with a xtal set.
Has it worked for you and if so,
how did you couple it to the set?
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You can couple off a secondary "pick up " loop
8 ft loop radio with cool hand capacitance shields https://m.youtube.com/watch?v=jxm2LQAO5ic.
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A tunable loop should do well in enhancing selectivity.
Never tried that with a xtal set.
Has it worked for you and if so,
how did you couple it to the set?
I think the consensus is to feed the loop with the wire, and the loop resonates/sets selectivity for the antenna system overall, keep in mind a high q loop can cut the bw down to a few hundred hz.
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You can couple off a secondary "pick up " loop
8 ft loop radio with cool hand capacitance shields https://m.youtube.com/watch?v=jxm2LQAO5ic.
Cool 8)
wonder if the XYL would let me put it in the living room.
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Tried tuning around a bit just before sunrise.
Caught a sports station ID as 15-30, probably WCKY Cincinnati.
The locals were mostly drowning out the DX as the sun came up but heard a faint signal...
thought the YL announcer said WIP "Sports Radio Philadelphia" but could not find a AM listing
for that call. Did find a WIP FM 94.1, anybody know the AM call and freq ?
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WTEL 610kc. Used to be WIP when I lived in Delaware about 10 years ago.
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WTEL 610kc. Used to be WIP when I lived in Delaware about 10 years ago.
OK, tnx.
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I did a drive by like in the loop video, it was not late enough for dx about 2300z . You can see why AVC was invented !
https://m.youtube.com/watch?v=miAH2tIH3nI
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Oh what fun they had in the teens and twenties!
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Oh what fun they had in the teens and twenties!
DX was a big deal.
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I did a drive by like in the loop video, it was not late enough for dx about 2300z . You can see why AVC was invented !
What kind of antenna are you using ?
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The hf antenna
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I built the Radio Netherlands one meter MW loop on a pvc frame and wooden base about 20 years ago. My wife didn't seem to mind but I wasn't allowed to take it outside or downstairs where the neighbors and the the in-laws might see it.
I never used it on anything but modern superhets I could feed with the coupling loop. There was an interesting thing with that loop, it was resonant on harmonics. You could nail the New Guinea and Indonesian stations with it on 90 meters. I even got Bangla Betar on 4880 kHz on 60 coming over the Pole a few times with that loop.
Then we got a cat who saw it as a toy. That was the end of the loop.
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I built the Radio Netherlands one meter MW loop on a pvc frame and wooden base about 20 years ago. My wife didn't seem to mind but I wasn't allowed to take it outside or downstairs where the neighbors and the the in-laws might see it.
I never used it on anything but modern superhets I could feed with the coupling loop. There was an interesting thing with that loop, it was resonant on harmonics. You could nail the New Guinea and Indonesian stations with it on 90 meters. I even got Bangla Betar on 4880 kHz on 60 coming over the Pole a few times with that loop.
Then we got a cat who saw it as a toy. That was the end of the loop.
Was that also the end of the cat ?
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The cat is now a world renowned harpist.
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.....Playing at the iconic Pearly Gates Concert Hall. SRO. ;D