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Total 263 documents matching your query.

221. Re: Topband: Shunt feed question (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 16 Oct 2019 17:00:49 +0000
Marty, You may be seeing errors in your readings due to broadcast pickup. This is common when modern R+Jx measurement tools are connected to large antenna structures. Others have described ways aroun
/archives//html/Topband/2019-10/msg00132.html (9,836 bytes)

222. Topband: Hardening the 8 Circle Receiving Array (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Fri, 18 Oct 2019 15:52:14 +0000
Hi Folks, The Hi-Z Antennas brand amps already have a path to drain static as they are designed to produce 4 to 5 Volts DC on the element with an internal voltage divider. Attaching another resistor
/archives//html/Topband/2019-10/msg00152.html (9,227 bytes)

223. Re: Topband: Topband resource (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Tue, 14 Jan 2020 19:53:47 +0000
Yes, somewhat common in the "hollow state" device days(Tubes). Old also Wayne. Lee K7TJR Very good Jeff! See Google/Wikipedia.  Wiki says "on the order of 1 pf/inch." (You must be as old as I am . .
/archives//html/Topband/2020-01/msg00216.html (8,746 bytes)

224. Topband: Topband resource (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 15 Jan 2020 19:13:43 +0000
And from the Northwest I have a slightly different observation of horizontal/vertical questions. What I have noticed is this. I more or less equate Horizontal antennas with high angle and vertical wi
/archives//html/Topband/2020-01/msg00245.html (9,652 bytes)

225. Re: Topband: 9 circle RX array combiner board (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Mon, 2 Mar 2020 03:36:06 +0000
Hi Guys, I got advance information of the 2N5109 and its cousin the 2N3866 transistors demise. I used the 2N3866 in my older design Hi-Z 75 ohm preamp so this transistor should suffice in most preamp
/archives//html/Topband/2020-03/msg00023.html (11,871 bytes)

226. Topband: YCCC 9 Vertical Array Preamplifiers (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 4 Mar 2020 00:31:09 +0000
There seems to be some confusion about. Let me explain the significance of Joel's comment about the high impedance amplifiers. I have developed new versions of the Hi-Z amplifiers I use in the Hi-Z a
/archives//html/Topband/2020-03/msg00047.html (8,940 bytes)

227. Topband: YCCC 9 Vertical Array Preamplifiers (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 4 Mar 2020 09:39:03 +0000
Hello Henk and others, I can surely see your point about how interesting that would be to share all the circuit details. However you would have to understand that what you propose is exactly what I d
/archives//html/Topband/2020-03/msg00049.html (13,276 bytes)

228. Re: Topband: Hi Z amplifiers for 160m (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 11 Mar 2020 17:17:23 +0000
Greetings all, George has some very pertinent points here and only on one point I will disagree. What a Hi-Z amplifier needs to do is dependent on your aspirations of the size and quantity of element
/archives//html/Topband/2020-03/msg00112.html (11,120 bytes)

229. Re: Topband: Hi Z amplifiers for 160m (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 11 Mar 2020 17:37:01 +0000
Mouser 601- 25-7630 or 601-25-7660 [Lee K7TJR] Can you point to a place that sells them. I became a 'fan' of F termination, but have recently had second thoughts because of the bulkhead connector's q
/archives//html/Topband/2020-03/msg00115.html (8,075 bytes)

230. Re: Topband: Hi Z amplifiers for 160m (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Thu, 12 Mar 2020 02:22:07 +0000
Hello John and all, Concerning the adding the noise in a typical array. If the noise was coherent or exactly the same signal from each element/amp the summed noise would indeed be 8 times. However ci
/archives//html/Topband/2020-03/msg00123.html (15,397 bytes)

231. Re: Topband: Hi Z amplifiers for 160m (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Thu, 12 Mar 2020 05:23:41 +0000
Mike and all, Well stated Mike. It's been a long time since we have conversed. The modifier to this is when the signals coming into the combiner are no longer in phase or coherent. This as a result o
/archives//html/Topband/2020-03/msg00127.html (19,783 bytes)

232. Re: Topband: Hi Z amplifiers for 160m (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Thu, 12 Mar 2020 20:15:41 +0000
John, Yes of course you are quite correct. I stand corrected. I should not have used the word power. My thinking was along the line of what Mike W4EF posted. Just did not say it right. Also, I have n
/archives//html/Topband/2020-03/msg00133.html (18,710 bytes)

233. Re: Topband: Slightly OT - amplifier noise (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Mon, 16 Mar 2020 21:32:00 +0000
Dont forget there is gain in the signal paths. That first AUX input stage is a Norton configuration amp with gain controlled by the unknown transformer ratios. The two J-310's that sum the signals al
/archives//html/Topband/2020-03/msg00204.html (15,874 bytes)

234. Re: Topband: Slightly OT - amplifier noise (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Mon, 16 Mar 2020 22:30:38 +0000
Hi Dave, In my experience that is not a typical Norton amplifier gain . Most would be considerably in excess of that at 11 or 19 dB. They can run from 5 to 19 dB or so but what would be the purpose o
/archives//html/Topband/2020-03/msg00208.html (17,805 bytes)

235. Topband: RG-6 Delay cables (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 8 Apr 2020 17:37:47 +0000
Good morning from Oregon Top-Band people, I decided to re-do some previous tests of the common 75 ohm RG-6 cable I use and is used for delay cables in many places for top-band receiving systems. I ju
/archives//html/Topband/2020-04/msg00029.html (8,125 bytes)

236. Re: Topband: RG-6 Delay cables (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 8 Apr 2020 19:28:13 +0000
Hi Mike, I make the Hi-Z Antennas receiving arrays and I am always looking for ways to make them work better. Attention to detail has been the key to success in my endeavors. I had made some early te
/archives//html/Topband/2020-04/msg00035.html (10,440 bytes)

237. Re: Topband: RG-6 Delay cables (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 8 Apr 2020 20:28:21 +0000
Hi Rick, Agreed, the numbers surely seemed too good to be true. I also researched cable delays versus temperature at various manufacturers. I found no data at the low bands we use. I found just enoug
/archives//html/Topband/2020-04/msg00038.html (9,844 bytes)

238. Re: Topband: RG-6 Delay cables (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Wed, 8 Apr 2020 21:11:19 +0000
Robin WA6CDR mentioned this to me in an earlier exchange this AM. It was not me. Should have mentioned that before. Sorry Robin, You the Man! Lee K7TJR Very astute. You may have explained this parado
/archives//html/Topband/2020-04/msg00040.html (9,261 bytes)

239. Re: Topband: RG-6 Delay cables (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Thu, 9 Apr 2020 03:57:23 +0000
More on the cable testing, Thinking along the lines Rick was I decided to retest the same cable to see if the results were repeatable. The original phase shift for both room temperatures was 59 deg.
/archives//html/Topband/2020-04/msg00044.html (10,872 bytes)

240. Re: Topband: Loop on the ground as a counterpoise (score: 1)
Author: Lee STRAHAN <k7tjr@msn.com>
Date: Thu, 7 May 2020 04:52:28 +0000
Greetings All, It seems this discussion has morphed into a discussion on ground planes for regular vertical antennas where if I read the authors description correctly he is using a Hi-Z amplifier. Th
/archives//html/Topband/2020-05/msg00027.html (12,727 bytes)


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