Rob Lenski
2009 Shortwave Active Receiver
Stations Heard: 64
This year I entered a dual acorn (955 triode) set for use on shortwave. The set is pretty much a copy of the 6C8G set in the 1934 shortwave tuning manual, except rather than use a single twin triode, I used two tubes. I also ran 150 volts to the tube handling the amplifying duties, but knocked the detector tube's plate voltage down to ~28 volts.
You may notice in the photo that the tuning coil and detector tube are on a raised bracket so as to keep them close to the tuning and throttle caps. This allows for shorter wiring which seemed to help reduce some of the problems that I initially had running this circuit. It may also have helped that the 955 triode has a lower amplification factor than the 6C8G, which it seems to me makes for an easier to use set. Having said that though, the set still had plenty of volume.
If you look at the lower right corner of the photo, you'll notice a bit of magnet wire. For the antenna connection I simply used a gimmick capacitor, which is simply two short lengths of insulated wire twisted together, but not connected electrically. It makes an itty-bitty capacitor. I found that this set does not like too tight of an antenna connection. If it's too tight, the throttle capacitor won't have sufficient capacitance and the set won't regenerate.
All in all, this circuit is easy to build, was a joy to operate, and really pulls in the signals. Much of Europe, and Asia can be heard. If you use acorn tubes you can build a fairly small set, and unlike many other tubes, the filaments in the 955's glow quite brightly.
Log
Date # Time Station Frequency
8/1/2009
1 8:20 Radio Australia 9580
2 19:07 Radio Bulgaria 9700
3 19:11 Voice of Greece 9420
4 19:17 Voice of Russia 9890
5 19:28 Voice of Russia 9665
6 19:40 WWV 10000
7 20:10 WINB Red Lion PA 9265
8 20:12 Albanai, Radio Tirana 9345
9 20:13 WTJC Newport, NC 9370
10 20:15 Radio Prague 9440
11 20:18 WYFR Family Radio Worldwide 9505
12 20:22 China Radio Int'l 9570
13 20:23 Bucharest Radio Romania Int'l 9580
14 20:28 Int'l Radio of Serbia 9675
15 20:50 Zambia CVC Int'l 4965
16 20:59 Radio Canada Int'l 5190
17 21:00 Voice of Vietnam 5265
18 21:04 Radio Prague 5290
19 20:35 Radio Sweden 6010
8/2/2009
20 18:04 Equatorial Guinea & Radio Africa 15190
21 18:09 Radio Romania Int'l 9790
22 18:15 WWRB 9385
23 18:16 USA VOA 9415
24 18:23 WTJC Newport, NC 9370
25 18:25 Moldavia 9665
26 18:35 Voice of Turkey 9830
27 18:42 WYFR Family Radio Worldwide 10830
28 20:12 NHK World, Radio Japan 6145
29 20:14 Anguilla, Worldwide Univ Network 6090
30 20:16 Spain Radio Exterior Espana 6055
31 20:20 China Radio Int'l 6020
32 20:35 WWCR 9980
33 20:36 WEWN 11520
34 20:42 Radio Canada Int'l 13725
35 20:44 Cuba, Radio Habanna Cuba 13760
8/3/2009
36 19:25 WWCR 7465
37 19:30 Venezuela 15250
38 20:17 Radio Ukraine Int'l 7440
39 20:27 WWRB 3185
40 20:28 WWRB 3215
41 20:29 CHU (Time Canada) 3330
8/4/2009
42 17:02 EWTN 15610
43 18:53 WWV 15000
44 19:17 China Radio Int'l 6145
45 19:20 China Radio Int'l 11841
46 20:09 Radio Thailand World Service 15275
47 20:15 Radio Canada Int'l 6100
48 20:20 WBCQ 5110
49 20:24 WINB Red Lion PA 9265
50 20:30 WWCR 5935
51 20:32 WYFR Family Radio Worldwide 5950
52 20:34 CHU (Time Canada) 7335
53 20:36 WYFR Family Radio Worldwide 15440
54 20:40 Radio Slovakia Int'l 5930
55 21:01 Radio Slovakia Int'l 9440
8/5/2009
56 6:39 WWCR 5070
57 15:59 UK BBC World Service 12095
58 16:07 Albania, Radio Tirana 13640
8/7/2009
59 21:25 Voice of Vietnam 6175
60 21:32 Radio Havana Cuba 6140
61 21:34 Radio Havana Cuba 6000
62 21:57 WYFR Family Radio Worldwide 15440
63 22:09 South Korea KBS World Radio 9580
64 22:10 Radio Taiwan Int'l 5950