Date: Wed, 1 Jun 94 04:30:09 PDT From: Ham-Ant Mailing List and Newsgroup Errors-To: Ham-Ant-Errors@UCSD.Edu Reply-To: Ham-Ant@UCSD.Edu Precedence: Bulk Subject: Ham-Ant Digest V94 #165 To: Ham-Ant Ham-Ant Digest Wed, 1 Jun 94 Volume 94 : Issue 165 Today's Topics: 2 meter thru-glass (Saturn) Apartment rain gutters on 40M (3 msgs) Dipole help (5 msgs) ES Grid Dip Oscillator or Noise Bridge? (2 msgs) Maltese quad where to buy Channel Master FM antenna? recommendations on signal amp? Send Replies or notes for publication to: Send subscription requests to: Problems you can't solve otherwise to brian@ucsd.edu. Archives of past issues of the Ham-Ant Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives/ham-ant". We trust that readers are intelligent enough to realize that all text herein consists of personal comments and does not represent the official policies or positions of any party. Your mileage may vary. So there. ---------------------------------------------------------------------- Date: 31 May 1994 21:50:53 GMT From: ihnp4.ucsd.edu!swrinde!cs.utexas.edu!convex!news.duke.edu!solaris.cc.vt.edu!news.ans.net!sitka.wsipc.wednet.edu!connected.com!openwx!hays@network.ucsd.edu Subject: 2 meter thru-glass (Saturn) To: ham-ant@ucsd.edu David Drumheller (drumhell@claudette.nrl.navy.mil) wrote: : Just adding another `branch' to this thread... : A few months ago I posted a few questions about through-the-glass : antennas. I had recently purchased a 1993 Saturn SL, and was wondering : what other Saturn owners had done to install through-the-glass on their : By the way, has anyone ever *removed* a through-the-glass antenna? How : difficult is it? Is the adhesive difficult to remove? Does it leave a : stain or mark on the glass? Is it difficult to avoid damage the antenna? : -- : David Drumheller, KA3QBQ phone: (202) 767-3524 : Acoustics Division, Code 7140 fax: (202) 404-7732 : Naval Research Laboratory : Washington, DC 20375-5350 e-mail: drumhell@claudette.nrl.navy.mil David, I also drive a '93 Saturn (SL2). I decided to bite the bullet and drill the chassis. I put an NMO mount in the lid to the trunk. It turns out that if you mount it a little back of the center of the lid, coax feeds nicely. I routed the coax to the front of the car (under the carpet, near the moldings). I then took my DR-590T (with remotable head) and mounted the body near the blower on the passenger side, and routed the cable up into the space under the dash. I mounted the head and microphone to the plastic molding which goes around the driver's console and the air vents. I figure that when it comes time to sell, I will replace the molding and put a cellular antenna on the NMO .... John D. Hays KD7UW Email: jhays@hays.org or hays@networx.com ------------------------------ Date: Tue, 31 May 94 11:37:02 EDT From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!usenet.ins.cwru.edu!ns.mcs.kent.edu!kira.cc.uakron.edu!malgudi.oar.net!hypnos!voxbox!jgrubs@network.ucsd.edu Subject: Apartment rain gutters on 40M To: ham-ant@ucsd.edu -----BEGIN PGP SIGNED MESSAGE----- davev@miles.ATkc.COM (David P. van De Kerk) writes: > My apartment building has a no antenna policy, but they have this beautiful > system of aluminum rain gutters going up and down the building. (two story) > so it's kind of like a long wire that goes up and down the building, directly > connected to the building. Anybody tried using the rain gutter on their > apartment? Does it work? How will the SWR be? I have an MFJ 945 C tuner > and a Radio Shack nearby for parts to make this work. What > should I feed it with? Right now, I have coax feeding it, which > I can receive with but haven't tried to transmit yet. Try one or another variation on shunt feeding. -----BEGIN PGP SIGNATURE----- Version: 2.6 iQCVAwUBLetaETDUWq8RWEeNAQHumwP/YiZD0Th1CWV2v8uttE5gluyMIqB/n6LK yibDbBjDHWTpDNwKd8WLJ4uWKjuunMhK/gv9qbotNTGugzWVqrXXRLtetbPqW5Kl fc0iwneuaAplR8+DRrqYhZIGjcQBf0Sk5aVhjmTGxeMbEieLiZIvNIVQCRAJ2gTF OgNt/3T3lUs= =uzOy -----END PGP SIGNATURE----- +--------------------------------------------------------------------------+ | Jim Grubs, W8GRT Voxbox Enterprises THIS SPACE FOR RENT | | jgrubs@voxbox.norden1.com 6817 Maplewood Ave. RATES REASONABLE | | Fido: 1:234/1.0 Sylvania, Ohio 43560 Home: 419/882-2697 | | AMATEUR RADIO - The National Park of the Mind | +--------------------------------------------------------------------------+ ------------------------------ Date: 31 May 1994 17:30:41 GMT From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!peri.acs.ohio-state.edu!rdixon@network.ucsd.edu Subject: Apartment rain gutters on 40M To: ham-ant@ucsd.edu |> |> davev@miles.ATkc.COM (David P. van De Kerk) writes: |> |> > My apartment building has a no antenna policy, but they have this beautiful |> > system of aluminum rain gutters going up and down the building. (two story) |> > so it's kind of like a long wire that goes up and down the building, directly |> > connected to the building. Anybody tried using the rain gutter on their |> > apartment? Does it work? How will the SWR be? I have an MFJ 945 C tuner |> > and a Radio Shack nearby for parts to make this work. What |> > should I feed it with? Right now, I have coax feeding it, which |> > I can receive with but haven't tried to transmit yet. |> I have used the rain gutter system on a house as an antenna. I ran a single wire out the window, and connected it to the metal gutter. I tuned it with a longwire antenna tuner, and it worked fine. I told people during QSO's and on my QSL card that I was using an "end fed rain gutter" as an antenna (even though it was actually fed somewhere nearer the middle). I worked lots of DX on 40 and 20 meters with 90 watts. Bob W8ERD ------------------------------ Date: 31 May 94 21:31:30 GMT From: sdd.hp.com!col.hp.com!srgenprp!alanb@hplabs.hpl.hp.com Subject: Apartment rain gutters on 40M To: ham-ant@ucsd.edu Andy Domonkos (domonkos@delphi.com) wrote: : >My apartment building has a no antenna policy, but they have this beautiful : >system of aluminum rain gutters going up and down the building. (two story) : >so it's kind of like a long wire that goes up and down the building, : directly connected to the building. Anybody tried using the rain gutter on : >their apartment? Does it work? How will the SWR be? I have an MFJ 945 C : >tuner and a Radio Shack nearby for parts to make this work. What : >should I feed it with? Right now, I have coax feeding it, which : >I can receive with but haven't tried to transmit yet. : It'll work w/tuner but unless yu can strap the gutter joints w/jumpers man : you'll have some bad RFI problems (rectification at the gutter joints). Or you may get lucky and have no RFI problems. Try it, and check your own TV for interference. (Check each TV channel on every amateur band you intend to use.) It would be a good idea to re-check every now and then, especially when the weather changes. : If you have access to an attic (even if only a crawlspace) a slinky dipole : will work great. ... If you have rusty, rectifying rain gutters, the attic dipole can cause problems also, due to RF pickup by the rain gutters. Do the TVI test with your own TV before doing any extensive operating. AL N1AL ------------------------------ Date: 31 May 1994 16:50:29 GMT From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!europa.eng.gtefsd.com!news.umbc.edu!eff!news.kei.com!ssd.intel.com!chnews!cmoore@network.ucsd.edu Subject: Dipole help To: ham-ant@ucsd.edu armond@delphi.com wrote: : the human ear, on a steady tone, can detect a 2dB difference.....for many, : a 1dB difference can be discerned. I assume this is in response to my statement that a human ear cannot detect a 2dB difference. That statement was in the context of a 2dB difference in radiated RF from an antenna. Some sort of AGC is usually involved at the receiving end. So I should have been more specific. Human ears cannot detect a 2dB difference in received RF signal strength under normal HF conditions using average HF receivers. After all, 2dB is 1/3 of an S-unit. I personally, have trouble detecting a one S-unit change (6dB) with the AGC on since the audio does not change as much as the RF. The dynamic range of the audio section of an average superhet is much less than the dynamic range of the RF section. 73, KG7BK, CecilMoore@delphi.com ------------------------------ Date: 31 May 1994 18:24:14 GMT From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!vixen.cso.uiuc.edu!usenet@network.ucsd.edu Subject: Dipole help To: ham-ant@ucsd.edu In <2sfpsl$a50@chnews.intel.com>, cmoore@ilx018.intel.com (Cecil A. Moore -FT-~) writes: >armond@delphi.com wrote: >: the human ear, on a steady tone, can detect a 2dB difference.....for many, >: a 1dB difference can be discerned. > >I assume this is in response to my statement that a human ear cannot >detect a 2dB difference. That statement was in the context of a 2dB >difference in radiated RF from an antenna. Some sort of AGC is usually >involved at the receiving end. So I should have been more specific. > >Human ears cannot detect a 2dB difference in received RF signal strength >under normal HF conditions using average HF receivers. After all, 2dB is >1/3 of an S-unit. I personally, have trouble detecting a one S-unit >change (6dB) with the AGC on since the audio does not change as much as >the RF. The dynamic range of the audio section of an average superhet is >much less than the dynamic range of the RF section. > >73, KG7BK, CecilMoore@delphi.com > Here is a more valid question: If one station is +2db over the other one, can you tell a difference? If both are calling you, which one would you copy better? Ignacy Misztal Ham radio: NO9E, SP8FWB E-mail: ignacy@uiuc.edu University Of Illinois 1207 W. Gregory Dr., Urbana, IL 61801, USA tel. (217) 244-3164 Fax: (217) 333-8286 ------------------------------ Date: 31 May 1994 20:54:26 GMT From: ihnp4.ucsd.edu!usc!cs.utexas.edu!convex!news.duke.edu!eff!news.kei.com!ssd.intel.com!chnews!cmoore@network.ucsd.edu Subject: Dipole help To: ham-ant@ucsd.edu Ignacy Misztal (ignacy@misz.animal.uiuc.edu) wrote: : Here is a more valid question: If one station is +2db over the other : one, can you tell a difference? If both are calling you, which one : would you copy better? Ignacy Misztal Ham radio: NO9E, SP8FWB Hi Ignacy, assuming the two HF stations are within 2dB (RF) of each other and on the same frequency, you could not tell the difference just by listening and you would be able to copy neither one "if both are calling you" simultaneously on SSB. On CW you could probably measure a difference with a meter but not with your ears. Can you tell the difference between an S9 station and an S9+2dB station? I can't with my ears nor with my S-meter. Under certain threshold conditions, you might be barely unable to read an S1 station and barely able to read an S1+2dB station but QSB would, no doubt, make both QSOs unsuccessful. Sometimes QSB varies my received signals by 12dB or more every few seconds. Threshold QSOs are really tough. 73, KG7BK, CecilMoore@delphi.com ------------------------------ Date: 1 Jun 1994 00:26:09 GMT From: ihnp4.ucsd.edu!library.ucla.edu!europa.eng.gtefsd.com!news.umbc.edu!eff!news.kei.com!ssd.intel.com!chnews!cmoore@network.ucsd.edu Subject: Dipole help To: ham-ant@ucsd.edu Robert Casey (wa2ise@netcom.com) wrote: : If on FM, capture effect will only let you hear the stronger station, : and wipe out the one 2dB weaker. Hi Robert, I think maybe there has to be more than 2dB difference for the capture effect to wipe out the weaker station. During net checkins, I often hear doubling, tripling, etc. where I cannot understand anybody because I'm hearing everybody all at once, just like SSB. 73, KG7BK, CecilMoore@delphi.com ------------------------------ Date: Wed, 1 Jun 1994 06:16:19 GMT From: ihnp4.ucsd.edu!news.cerf.net!ent-img.com!wb6hqk!bart@network.ucsd.edu Subject: Dipole help To: ham-ant@ucsd.edu In article <2sfpsl$a50@chnews.intel.com>, > >Human ears cannot detect a 2dB difference in received RF signal strength >under normal HF conditions using average HF receivers. After all, 2dB is >1/3 of an S-unit. I personally, have trouble detecting a one S-unit >change (6dB) with the AGC on since the audio does not change as much as >the RF. The dynamic range of the audio section of an average superhet is >much less than the dynamic range of the RF section. The purpose of the AGC in a SSB receiver is to maintain a constant audio output level for a varying input amplitude. Assuming the AGC is working well, and the Signal to Noise ratio (SNR) is somewhat greater than one, a 2dB increase in signal at the receiver input will cause the AGC to back off by 2 dB maintaining a constant output signal level but decreasing the background noise by 2 dB. For SNR's near the threshold of intelligible speech, (10 db approx) the 2dB increase can be quite beneficial, but as the SNR increases beyond 20 db or so, the difference will be negligible and ideally the transmitter power can be reduced to save power and reduce QRM. In the case of a fading channel the average SNR required will be higher to allow for the short term fades and the analysis is more complicated. bart wb6hqk bart@wb6hqk.ent-img.com ------------------------------ Date: 31 May 94 13:27:00 GMT From: news-mail-gateway@ucsd.edu Subject: ES To: ham-ant@ucsd.edu Thanks to all for correcting my mistaken impresions about the origin of "es". Obviously, it isn't Spanish. I'm ESpecially grateful to Dave, KZ1O for giving us chapter and verse..... "No one is exempt from speaking nonsense. The only misfortune is to do it solemnly." -Montaigne . ... .... .. .... .. KD1DJ, Al ------------------------------ Date: Tue, 31 May 1994 23:39:52 GMT From: news!wrs.com!jerald@uunet.uu.net Subject: Grid Dip Oscillator or Noise Bridge? To: ham-ant@ucsd.edu The budget is looking good for a new toy.... I am thinking of getting a piece of equipment to help me tune my new (and heretofore unerected) HF antenna and I debating the merits of couple of devices, MFJ is selling two devices that I think are a grid dip oscillator and a noise bridge [If i've got this wrong, please correct me] The Antenna Resistance Analyzer (tm) (I think) is a noise bridge. The Bandswitched Dip Meter (tm) (once again I think) is a grid dip oscillator. I can afford one but not both - so which one do I want? What I'd like to do with them, is help me set and tune my antenna (tenatively a inverted-v into a transmatch) Afterward, I'd like to use it to help me tune in all those interesting stations on bands I can't use. Tune up in a band for the best possible return out of the receiver? Am I all wet here? I know I'm confused. Any help would be appreciated. Thanks, KC6RTO A A -- Jerald R. Pendleton Email: jerald@wrs.com, Personal Email: jrpend@netcom.com The preceeding message represents only the opinon of the author. This do not represent the opinions/positions of Wind River Systems, my mother, my wife or my poodle. ------------------------------ Date: 1 Jun 1994 00:57:50 GMT From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!europa.eng.gtefsd.com!news.umbc.edu!eff!news.kei.com!ssd.intel.com!chnews!cmoore@network.ucsd.edu Subject: Grid Dip Oscillator or Noise Bridge? To: ham-ant@ucsd.edu Jerald Pendleton (jerald@wrs.com) wrote: : Am I all wet here? I know I'm confused. Any help would : be appreciated. Thanks, KC6RTO Jerald, IMHO the best single "instrument" you could purchase is an antenna tuner. Put up a dipole, feed it with ladder-line, and use the antenna tuner to work all bands. Don't worry about resonance... the antenna tuner tunes the antenna system to resonance. Don't worry about SWR... it doesn't matter much with ladder-line. I really don't need to measure anything about my antenna except the SWR that the transmitter sees. Good dipole lengths are 102 ft. and mine is 88 ft. Both lengths work 80m-10m. 73 and good luck, KG7BK, CecilMoore@delphi.com ------------------------------ Date: 31 May 1994 12:21:06 -0400 From: newstf01.cr1.aol.com!search01.news.aol.com!not-for-mail@uunet.uu.net Subject: Maltese quad To: ham-ant@ucsd.edu In article <2sd04e$ctl@ugle.unit.no>, kenneth@Lise.Unit.NO (Kenneth Opskar) writes: Well, in the Apr or May issue of CQ, they featured this ant. the info on it is to long to post, but if you can not find that issue, I could possibly mail the info to you. let me know. 73 Randy KE6HCI@m6qmy.#nocal.ca.usa.noam internet Randy753@aol.com ------------------------------ Date: 31 May 1994 13:37:14 GMT From: newsgate.watson.ibm.com!watnews.watson.ibm.com!locutus.rchland.ibm.com!georgtest.endicott.ibm.com!ludovids@uunet.uu.net Subject: where to buy Channel Master FM antenna? recommendations on signal amp? To: ham-ant@ucsd.edu Wasn't sure wether to post this here, or on an audio group, but here goes... Could someone tell me where I can get a good price on a Channel Master 3025 FM antenna? (was model #4408) Preferably close to, but not in, New York state to avoid sales tax on a mail order. Also, any recommendations on a signal boosting amp to use with the antenna? I'm trying to receive a signal from an apparently low-powered translator that's about 85 miles from me. Thanks alot, Dave Ludovici ludo@vnet.ibm.com ------------------------------ Date: Tue, 31 May 1994 22:29:53 GMT From: ihnp4.ucsd.edu!library.ucla.edu!csulb.edu!csus.edu!netcom.com!wa2ise@network.ucsd.edu To: ham-ant@ucsd.edu References , <2sfpsl$a50@chnews.intel.com>, <2sfvce$dl@vixen.cso.uiuc.edu> Subject : Re: Dipole help In article <2sfvce$dl@vixen.cso.uiuc.edu> ignacy@uiuc.edu (Ignacy Misztal) writes: >Here is a more valid question: If one station is +2db over the other >one, can you tell a difference? If both are calling you, which one >would you copy better? > If on FM, capture effect will only let you hear the stronger station, and wipe out the one 2dB weaker. ------------------------------ End of Ham-Ant Digest V94 #165 ******************************