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Date: Sun, 23 Jan 94 23:40:04 PST From: Info-Hams Mailing List and Newsgroup <info-hams@ucsd.edu> Errors-To: Info-Hams-Errors@UCSD.Edu Reply-To: Info-Hams@UCSD.Edu Precedence: Bulk Subject: Info-Hams Digest V94 #69 To: Info-Hams Info-Hams Digest Sun, 23 Jan 94 Volume 94 : Issue 69 Today's Topics: ??? Are there any RS232C cards for PCMCIA? Bird Problems with Yagi Antenna callsign servers CW Books CW filters and DSP-9 (2 msgs) Daily Summary of Solar Geophysical Activity for 22 January International Callsign Server The differences in CW filter performance Send Replies or notes for publication to: <Info-Hams@UCSD.Edu> Send subscription requests to: <Info-Hams-REQUEST@UCSD.Edu> Problems you can't solve otherwise to brian@ucsd.edu. Archives of past issues of the Info-Hams Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives/info-hams". 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: Thu, 20 Jan 1994 01:32:18 GMT From: usenet.coe.montana.edu!netnews.nwnet.net!ns1.nodak.edu!plains!drusteba@decwrl.dec.com Subject: ??? To: info-hams@ucsd.edu ------------------------------ Date: 21 Jan 94 10:00:22 GMT From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!cs.utexas.edu!swrinde!sgiblab!sgigate.sgi.com!olivea!koriel!sh.wide!wnoc-tyo-news!aist-nara!ccsparc01!icspub!ce-gw!ee!kitagawa@network.ucsd. Subject: Are there any RS232C cards for PCMCIA? To: info-hams@ucsd.edu Thank you everyone who responded by mail or news. I> Are there any RS232C cards for PCMCIA slot? > you may want to consider "dockable" laptops. Unfortunately I've never heard of the docking station for my favorite T1950. I am told that there are some serial interface cards for PCMCIA (by IBM and others) but still don't have specific model numbers. I> I'm also looking for PCMCIA Ethernet cards for 10base-2 (Coax) I've got the info that there is one for T1950; NWETH02 Noteworthy 10base2 PCMCIA type II Ethernet card. > You could go with the old, yet trusty Xircom 10-Base2 external LAN > adapter.... Oh, it might be even better if I can save a PCMCIA slot. Thanks! I> FYI (to Hams only, probably contesters only): Why do I need so many I> serial ports? Yes, I want to run CT (by K1EA) in multi-multi station. I am informed that CT ver 8.47 has implemented a single-directional loop which requires only one serial port per computer. If it works fine, I don't need a serial port card nor an Ethernet card, i.e. the best solution for me. Masahiro Kitagawa <kitagawa@ee.es.osaka-u.ac.jp> Electrical Engineering, Engineering Science, Osaka University ------------------------------ Date: Sun, 23 Jan 1994 06:28:08 GMT From: sdd.hp.com!nigel.msen.com!usenet.ins.cwru.edu!ukma!news2.uunet.ca!iceonline!icebox!janc@network.ucsd.edu Subject: Bird Problems with Yagi Antenna To: info-hams@ucsd.edu >This produces a messy roof and a serious hazard to parked cars, cats and >small children on the ground :-) > >Also, however, the elements have been getting torqued seriously out of >plane by the weight of the lil' chirpers. They seem not to have an eye >for symmetry and apparently don't understand about balanced loads, >balanced feed lines, or the like. > Some of the local hams in this area have mounted plastic Owls atop the antenna and tuned to compensate (if and when necessary). It seems to keep the real feathered fiends at bay. ----------------------------------------------------------------------------- : If you eat a live toad first thing in the janc@icebox.iceonline.com : morning, nothing worse will happen to you all : day. : To you or the toad. ----------------------------------------------------------------------------- ------------------------------ Date: Fri, 21 Jan 1994 21:34:58 GMT From: utcsri!newsflash.concordia.ca!sifon!clouso.crim.ca!hobbit.ireq.hydro.qc.ca!barde!vaillan@uunet.uu.net Subject: callsign servers To: info-hams@ucsd.edu In article 7Fy@ucdavis.edu, ez006683@othello.ucdavis.edu (Daniel D. Todd) writes: >Hi all, >I was trying to access the buffalo callsign server but I keep getting an >error. Is this a network problem a local problem or an operator problem. > >othello% telnet electra.cs.buffalo.edu 2000 >telnet: service to this port is not available >othello% telnet callsign.cs.buffalo.edu 2000 >telnet: service to this port is not available >othello% telnet 128.205.32.2 2000 >telnet: service to this port is not available >othello% > >Thanks for the help, >Dan > >-- >*---------------------------------------------------------------------* >* Daniel D. Todd Packet: KC6UUD@KE6LW.#nocal.ca.usa * >* Internet: ddtodd@ucdavis.edu * >* Snail Mail: 1750 Hanover #102 * >* Davis CA 95616 * >*---------------------------------------------------------------------* >* I do not speak for the University of California.... * >* and it sure as hell doesn't speak for me!! * >*---------------------------------------------------------------------* > You must have network problems... Here is what I get: telnet 128.205.32.2 2000 Trying 128.205.32.2 ... Connected to 128.205.32.2. Escape character is '^]'. Callbook v1.3 Bug reports to bowen@cs.buffalo.edu Type 'help' for help >> call kc6uud Call-Sign: KC6UUD Class: TECHNICIAN Real Name: DANIEL D TODD Birthday: DEC 19, 1966 Mailing Address: 1411 WAKE FOREST 6, DAVIS, CA 95616 Valid From: MAY 7, 1991 To: MAY 7, 2001 >> 73 Clem. --- Clement Vaillancourt, | Institut de Recherche d'Hydro-Quebec Analyste, | Varennes, P. Quebec, Canada, J3X 1S1 Informatique scientifique | Tel:+1 514 652 8238 Fax:+1 514 652 8309 vaillan@ireq.hydro.qc.ca | Radio-amateur: VE2HQJ@VE2CRL.PQ.CAN.NA ------------------------------ Date: Thu, 20 Jan 1994 21:57:04 GMT From: library.ucla.edu!agate!howland.reston.ans.net!cs.utexas.edu!swrinde!sgiblab!pacbell.com!unet!white!johng@network.ucsd.edu Subject: CW Books To: info-hams@ucsd.edu Ok, I've gone though the 200 or so unexpired articles, as well as the FAQ (probably not closely enough) and below is the closest my question has come to being answered. In article <2hebl3$2l9@news.acns.nwu.edu> rdewan@casbah.acns.nwu.edu (Rajiv Dewan) writes: >In article <CJqtFz.61@wri.com>, Bruce Pea <pea@wri.com> wrote: >>Can anyone recommend some good books on copying code?? >> >>Next test date is in March here, and I want to be ready >>to "ace" the 13wpm general class code test. I'm using >>SuperMorse and listening to code on my radio. I remember > >Noting the lack of a call sign in you sig, I assume that you >are not a ham yet. So I will not recommend getting on the air >and using it. ... [delete] ... My question is: If I pass the 13 wpm test, do I also have to pass the 5 wpm test? Or in other words; Can I get a General class license by passing the written tests for Novice, Technician and General and then pass ONLY the General CW test? I am interested in a General class license because of the privileges it provides but I am not that hot about learning CW at 5 wpm, then having to bump up to 13 wpm. I've listened to 5 and 13 wpm and they sound like two different languages! I'm pretty confident that I can be proficient at 13-15 wpm with plenty of practice. Any thoughts on how 'practical' this ambition is? Am I setting myself up for 'too much' work by skipping over the 5 wpm rate? -- John Gratton | johng@net.com Hans Christian 33 "Nakia" | (415)780-5774 The last time an informal vote on "should we split rec.boats" was taken, the motion was defeated 67 to 18. Before you start it again, please consider that. ------------------------------ Date: 21 Jan 1994 22:36:55 GMT From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!cs.utexas.edu!geraldo.cc.utexas.edu!astro.as.utexas.edu!oo7@network.ucsd.edu Subject: CW filters and DSP-9 To: info-hams@ucsd.edu yee@mipg.upenn.edu (Conway Yee) asks: >>When I look at CW filters, I see advertised bandwidths of between circa >>250Hz to 600Hz. What are the difference? The 250 Hz ones have a bandwidth of 250 Hz and the 600 Hz ones have a bandwidth of 600 Hz. That are[sic] the difference. What do you mean? Ref the DSP-9 postings, I have used mine a few times and am still not sure that it is doing anything for me on CW. It's cute having a 100 Hz width filter but, as someone mentioned, when it cuts out your sidetone you think twice about using it. So far, I've found that the fiddling around adjusting the receiver output for signals of different level as well as playing with the gain on the DSP-9 is distracting when tuning the bands. There is a narrow range of signal strengths where the DSP really helps. If the signal/noise is already 10 I don't need it to be 100, and when it's 1, the DSP doesn't really help. I need to play with it some more, I'm sure. It should be useful on phone, when I get around to that. Taking out the jammers and tuners-up on top of DX stations is useful, but it's not saying much for the state of amateur radio if the DSP boxes are primarily of use for removing deliberate human (or quasi-human) QRM. As far better ops than I have said, sometimes the best filter is the one between your ears. Derek "up lid" Wills (AA5BT, G3NMX) Department of Astronomy, University of Texas, Austin TX 78712. (512-471-1392) oo7@astro.as.utexas.edu ------------------------------ Date: 21 Jan 94 18:34:27 From: ucsnews!newshub.sdsu.edu!usc!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!msuinfo!netnews.upenn.edu!mipg.upenn.edu!yee@network.ucsd.edu Subject: CW filters and DSP-9 To: info-hams@ucsd.edu I ask a poorly phrased question: >When I look at CW filters, I see advertised bandwidths of between circa >250Hz to 600Hz. What are the difference? A poster replies: >The 250 Hz ones have a bandwidth of 250 Hz and the 600 Hz ones have a >bandwidth of 600 Hz. That are[sic] the difference. What do you mean? I am asking about the difference in CW performance. Is a narrower filter easier to copy or a wider one? -- Medical Image Processing Group | Conway Yee, N2JWQ 411 Blockley Hall | EMAIL : yee@mipg.upenn.edu 418 Service Drive | VOICE : 1 (215) 662-6780 Philadelphia, PA 19104-6021 (USA) | FAX : 1 (215) 898-9145 ------------------------------ Date: Sat, 22 Jan 1994 21:40:50 MST From: sdd.hp.com!cs.utexas.edu!howland.reston.ans.net!sol.ctr.columbia.edu!destroyer!nntp.cs.ubc.ca!alberta!adec23!ve6mgs!usenet@network.ucsd.edu Subject: Daily Summary of Solar Geophysical Activity for 22 January To: info-hams@ucsd.edu /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ DAILY SUMMARY OF SOLAR GEOPHYSICAL ACT 22 JANUARY, 1994 /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ (Based In-Part On SESC Observational Data) SOLAR AND GEOPHYSICAL ACT ----------------------------------------------------------- !!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 022, 01/22/94 10.7 FLUX=113.0 90-AVG=103 SSN=102 BKI=3212 0022 BAI=005 BGND-XRAY=B2.1 FLU1=7.1E+05 FLU10=1.0E+04 PKI=3212 2122 PAI=007 BOU-DEV=029,017,008,010,002,002,010,011 DEV-AVG=011 NT SWF=00:000 XRAY-MAX= C1.6 @ 0110UT XRAY-MIN= B1.9 @ 1808UT XRAY-AVG= B2.7 NEUTN-MAX= +002% @ 1205UT NEUTN-MIN= -002% @ 2005UT NEUTN-AVG= +0.0% PCA-MAX= +0.1DB @ 0745UT PCA-MIN= -0.4DB @ 1500UT PCA-AVG= -0.0DB BOUTF-MAX=55348NT @ 0446UT BOUTF-MIN=55328NT @ 1925UT BOUTF-AVG=55341NT GOES7-MAX=P:+000NT@ 0000UT GOES7-MIN=N:+000NT@ 0000UT G7-AVG=+060,+000,+000 GOES6-MAX=P:+127NT@ 1950UT GOES6-MIN=N:-061NT@ 0601UT G6-AVG=+081,+032,-031 FLUXFCST=STD:110,110,110;SESC:110,110,110 BAI/PAI-FCST=005,005,005/010,010,010 KFCST=1111 2111 0101 2111 27DAY-AP=007,005 27DAY-KP=2012 3223 1121 2211 WARNINGS=*SWF ALERTS= !!END-DATA!! NOTE: The Effective Sunspot Number for 21 JAN 94 is not available. The Full Kp Indices for 21 JAN 94 are: 2o 3- 1+ 1- 1+ 2- 3- 2o SYNOPSIS OF ACT -------------------- Solar activity was low during the past 24 hours. Region 7654 (N09W06) produced the only C-class x-ray event observed but has lost its delta magnetic configuration. Two new regions were numbered. Region 7658 (N12E16) is a simple bipolar group. Region 7659 (S13E47) was spotted briefly but is presently only plage and an arch filament system. Several unassociated Type III radio sweeps, and discrete radio bursts were reported. A large, inactive prominence is rotating over the east limb. Solar activity forecast: solar activity is expected to be low. Region 7654 retains the potential for occasional eruptive flares. The geomagnetic field has been at mostly quiet levels at middle geomagnetic latitudes for the past 24 hours. Some periods at active levels were observed at auroral latitudes. Geophysical activity forecast: the geomagnetic field is expected to be quiet for the next three days. Active conditions are possible on 26 Jan in response to disturbed solar wind associated with a filament disappearance on 21 Jan and an equatorial coronal hole which will be near central meridian on 23 Jan. Event probabilities 23 jan-25 jan Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF Green Geomagnetic activity probabilities 23 jan-25 jan A. Middle Latitudes Active 05/10/10 Minor Storm 01/05/05 Major-Severe Storm 01/01/01 B. High Latitudes Active 05/10/10 Minor Storm 01/05/05 Major-Severe Storm 01/01/01 HF propagation conditions were normal over all regions. Near-normal conditions should persist over the next 72 hours. High latitudes may begin seeing effects of the above-mentioned disturbance on 25 January. Otherwise, near-normal conditions are expected to continue. COPIES OF JOINT USAF/NOAA SESC SOLAR GEOPHYSICAL REPORTS ======================================================== REGIONS WIT ---------------------------------------------------------- NMBR LOCATION LO AREA Z LL NN MAG TYPE 7652 N04W23 220 0090 HSX 02 001 ALPHA 7654 N09W08 205 0610 CKI 09 032 BET 7657 N12W37 234 0080 DAO 06 012 BET 7658 N12E14 183 0010 BXO 05 005 BET 7659 S13E47 150 0010 BXO 02 002 BET 7656 S22W62 259 PLAGE REGIONS DUE TO RET NMBR LAT 7647 S15 096 7646 S09 087 7645 N13 085 7649 S19 079 LISTING OF SOLAR ENERGETIC EVENTS FOR 22 JANUARY, 1994 ------------------------------------------------------ A. ENERGETIC EVENTS: BEGIN MAX END RGN LOC XRAY OP 245MHZ 10CM SWEEP 0102 0109 0114 7654 N10W00 C1.6 SF 280 0246 0246 0246 110 0633 0633 0634 310 1911 1919 1926 7654 N08W10 B6.2 SF 290 1928 1928 1928 110 POSSIBLE CORONAL MASS EJECTION EVENTS FOR 22 JANUARY, 1994 ---------------------------------------------------------- BEGIN MAX END LOCATION TYPE SIZE DUR II IV NO EVENTS OBSERVED INFERRED CORONAL HOLES. LOCATIONS VALID AT 22/2400Z --------------------------------------------------- ISOLATED HOLES AND POLAR EXT EAST SOUTH WEST NORTH CAR TYPE POL AREA OBSN 57 N18W17 S10W57 S10W57 N18W17 250 ISO NEG 008 10830A 58 N20E29 S15E22 N02E07 N30E17 190 ISO POS 016 10830A SUMMARY OF FLARE EVENTS FOR THE PREVIOUS UTC DAY ------------------------------------------------ Date Begin Max End Xray Op Region Locn 2695 MHz 8800 MHz 15.4 GHz ------ ---- ---- ---- ---- -- ------ ------ --------- --------- --------- 21 Jan: 0324 0328 0332 B4.5 0758 0802 0809 B3.5 0816 0821 0838 SF 7654 N07E17 1019 1023 1025 B6.6 1140 1146 1155 B4.5 1610 1613 1616 B4.0 SF 7654 N08E12 2059 2103 2106 B4.6 SF 7654 N07E08 2308 2330 2340 B7.8 SF 7654 N06E07 REGION FLARE STATISTICS FOR THE PREVIOUS UTC DAY ------------------------------------------------ C M X S 1 2 3 4 Total (%) -- -- -- -- -- -- -- -- --- ------ Region 7654: 0 0 0 4 0 0 0 0 004 (50.0) Uncorrellated: 0 0 0 0 0 0 0 0 004 (50.0) Total Events: 008 optical and x-ray. EVENTS WIT ---------------------------------------------------------------- Date Begin Max End Xray Op Region Locn Sweeps/Optical Observations ------ ---- ---- ---- ---- -- ------ ------ --------------------------- 21 Jan: 0758 0802 0809 B3.5 III 2308 2330 2340 B7.8 SF 7654 N06E07 Continuum NOTES: All times are in Universal Time (UT). Characters preceding begin, max, and end times are defined as: B = Before, U = Uncertain, A = After. All times associated with x-ray flares (ex. flares which produce associated x-ray bursts) refer to the begin, max, and end times of the x-rays. Flares which are not associated with x-ray signatures use the optical observations to determine the begin, max, and end times. Acronyms used to identify sweeps and optical phenomena include: II = Type II Sweep Frequency Event III = Type III Sweep IV = Type IV Sweep V = Type V Sweep Continuum = Continuum Radio Event Loop = Loop Prominence System, Spray = Limb Spray, Surge = Bright Limb Surge, EPL = Eruptive Prominence on the Limb. ** End of Daily Report ** ------------------------------ Date: 24 Jan 94 03:38:02 GMT From: news-mail-gateway@ucsd.edu Subject: International Callsign Server To: info-hams@ucsd.edu Does anyone know of a server that can be TELNET'd that has a INTERNATIONAL callsign data base or CD-ROM on it? Whats the address? Buffalo.edu does not support international that I know of. /*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\ ! JD DELANCY | Lizzie Borden took an axe ! ! VM: 1-800-862-4511 Box 9276 | And plunged it deep in to the ! ! VOICE: 301-763-4943 or 3474 | VAX.. ! ! | Don't you just hate people who ! ! Email: k1zat@bah.com | do all the things YOU wanted to ! ! AX25: K1ZAT@K3HKI.#SOMD.MD.NA | do ?? ! /*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\/*\ ------------------------------ Date: 21 Jan 94 17:16:54 From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!agate!msuinfo!netnews.upenn.edu!mipg.upenn.edu!yee@network.ucsd.edu Subject: The differences in CW filter performance To: info-hams@ucsd.edu When I look at CW filters, I see advertised bandwidths of between circa 250Hz to 600Hz. What are the difference? -- Medical Image Processing Group | Conway Yee, N2JWQ 411 Blockley Hall | EMAIL : yee@mipg.upenn.edu 418 Service Drive | VOICE : 1 (215) 662-6780 Philadelphia, PA 19104-6021 (USA) | FAX : 1 (215) 898-9145 ------------------------------ Date: 23 Jan 1994 08:28:40 +0200 From: vixen.cso.uiuc.edu!howland.reston.ans.net!xlink.net!zib-berlin.de!netmbx.de!Germany.EU.net!EU.net!sunic!trane.uninett.no!news.eunet.no!nuug!news.eunet.fi!elvis.clinet.fi!@sdd.hp.com To: info-hams@ucsd.edu References <1994Jan11.150658.25191@ke4zv.atl.ga.us>, <940118.46856.LEEVANKOTEN@delphi.com>, <2hihn7$1vs@news.u.washington.edu>.unin Subject : Re: BRAIN CANCER, LEUKEMIA FROM HAM RADIO Man has a high risk to get at least brain cancer if listening too much 2m repeater OH2RAA in Helsinki. -- Jukka Salomaa jukka@clinet.fi OH2BUA phone +358 400 315 444 puhelin 9400 315 444 ------------------------------ Date: 22 Jan 1994 18:26:34 +0200 From: library.ucla.edu!agate!howland.reston.ans.net!pipex!sunic!news.funet.fi!butler.cc.tut.fi!lehtori.cc.tut.fi!not-for-mail@network.ucsd.edu To: info-hams@ucsd.edu References <2hple7$ti@geraldo.cc.utexas.edu>, <YEE.94Jan21183427@mipgsun.mipg.upenn.edu>, <2hpqci$m30@safety.ics.uci.edu>ht Subject : Re: CW filters and DSP-9 Clark Savage Turner (turner@safety.ics.uci.edu) wrote: > Most IF filters don't have much ring, though some, many audio filters > (except DSP I understand) can ring pretty badly. What should the audio filter frequency (and phase response) look like to avoid ringing. A high-Q single stage bandpass sounds horrible, but how does a filter with flat passband (eg. Butterworth or elliptic) sound like or is it really required to use Bessel-response in order to get rid of the hollow sound produced by noise peaks. Paul OH3LWR -------------------------------------------------------------------- Phone : +358-31-213 3657 X.400 : G=Paul S=Keinanen O=Elisa-Tampere A=ELISA C=FI Internet: Paul.Keinanen@Telebox.tele.fi Telex : 58-100 1825 (ATTN: Keinanen Paul) Mail : Hameenpuisto 42 A 26 FIN-33200 TAMPERE FINLAND ------------------------------ Date: 22 Jan 1994 18:25:41 +0200 From: library.ucla.edu!agate!howland.reston.ans.net!pipex!sunic!news.funet.fi!butler.cc.tut.fi!lehtori.cc.tut.fi!not-for-mail@network.ucsd.edu To: info-hams@ucsd.edu References <2hple7$ti@geraldo.cc.utexas.edu>, <YEE.94Jan21183427@mipgsun.mipg.upenn.edu>, <2hpqci$m30@safety.ics.uci.edu>ht Subject : Re: CW filters and DSP-9 Clark Savage Turner (turner@safety.ics.uci.edu) wrote: > In <YEE.94Jan21183427@mipgsun.mipg.upenn.edu> yee@mipg.upenn.edu > (Conway Yee) writes: > >I am asking about the difference in CW performance. Is a narrower > >filter easier to copy or a wider one? > This is a matter of personal taste for many of us. [deleted] > The filter can do two things for you : > > 1. Eliminate QRM nearby > 2. Quiet down the background noise. > > Reference number 2, some filters don't do so well at this, The filter bandwidth (which is usually defined as the bandwidth between the points where the frequency is -6 dB down from the maximum in the pass band) is not the only figure-of-merrit to look for. Equally important is the shape of the frequency response above and below the quoted bandwidth. This is usually specified with the -60 dB bandwidth and it indicates how much background noise will get through. There are 250 Hz (at -6 dB) filters with a 1.2 kHz -60 dB bandwidth and there are 500 Hz filters with a 800 Hz -60 dB bandwidth, so look carefully at the specifications. Despite broader passband, the latter filter is more effective to quiet down background noise and interfering signals a few hundred Hertz or more above or below the passband. Some manufacturers specify the passband bandwidth and the frequency offset from the center of the passband where the frequency response is -60 dB down, in the previous example +/- 600 Hz resp. +/- 400 Hz. Some even omit the +/- signs so that the figures look better. You can easily get the impresion that (+/-) 600 Hz is better than 800 Hz (total) bandwidth, so be carefull. Instead of the -60 dB bandwidth, sometimes the shape factor is given, which is simply the ratio of the -60 dB bandwidth to the -6 dB bandwith. The shape factor for the first example is 4.8 and 1.6 for the latter. In some cases the shape factor is given at a smaller attenuation e.g. 50 dB/6 dB to get smaller (and better) figures. Thus, it is very hard to select filters solely on the basis of passband bandwidth. As Clark pointed out in the begginning it is also a matter of personal taste. Paul OH3LWR -------------------------------------------------------------------- Phone : +358-31-213 3657 X.400 : G=Paul S=Keinanen O=Elisa-Tampere A=ELISA C=FI Internet: Paul.Keinanen@Telebox.tele.fi Telex : 58-100 1825 (ATTN: Keinanen Paul) Mail : Hameenpuisto 42 A 26 FIN-33200 TAMPERE FINLAND ------------------------------ Date: 21 Jan 1994 17:21:00 GMT From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!agate!linus!linus.mitre.org!mwvm.mitre.org!m14494@network.ucsd.edu To: info-hams@ucsd.edu References <2hk4tpINN125@abyss.West.Sun.COM>, <CJwDLy.4wz@news.direct.net>, <2hkd5iINN15h@abyss.West.Sun.COM> Subject : Re: Ramsey FX Transceivers Dana Myers writes: > The difference is that the IC24AT was factory built and then adjusted > by the factory to specified tolerances. I don't know about Icom specifically, but this is generally not true of consumer electronics. The published specs for most electronics represent an average based on samples taken from the production run. The statement at the end of the specs that says "Specifications subject to change without notice" really means "Your radio may not do this well". Only a very few manufacturers offer "guarenteed specs", in which each and every unit is guarenteed to meet the spec. When I bought a stereo receiver a while back, I went with Tandberg because unlike almost every other manfacturer, they guarentee their specs. Check the spec sheet for the radio in question; if it doesn't say they're guarenteed, they aren't. ***************************** * These are my opinions only* ***************************** ------------------------------ End of Info-Hams Digest V94 #69 ******************************