--------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4A00002 Date: 04/02/97 From: HARVEY HARBICHT Time: 09:55pm \/To: RAY WADE (Read 4 times) Subj: SWRs & more power DEBATE >Again I repeat. If your SWR is less than 1.5 to 1, QUIT SCREWING with >the antenna! It is a complete waste of time! I beg to differ. For the most part you are right, but consider this. My ICOM2000H mobile rig says "less than 1.5:1 of VSWR". Fine. So I adjust my antenna below 1.5 (about 1.4) and say "Good! Done!". The next time I'm parked in the backyard (or anywhere) and nearby objects raise it a bit, I'm over the safe limit and the radio might burn out. However if I keep working until it's 1.1......it can be raised by nearby objects while I'm driving around and not too much problem. Will it be raised. YES! Many times I've hooked up my MFJ thingie in place of the radio and watched the SWR go from 1.1:1 to 2:1 depending on where I was in the city. Everything's fine on the freeway until a truck passes me. The SWR goes WAY up and then back down. If I was set close to 1.5:1 this situation just might pop my finals. If I'm set at 1:1 a little raise would be safer. On the road 1:1. Parked in the yard 1.5:1. Driving along a tree lined street 2:1-1:1-2:1-1:1. You see? Just my opinion, but why not get it as low as possible to allow for changing conditions? The same for a roof mounted antenna. When it rains the SWR goes up a bit. Your "Stop at 1.5" could become 2:1 during wet weather, but my "Get it down to 1:1" allows for a safe error. KG9EV --- * Origin: *YOPS ]I[* 3.1 GIG * RA/FD/FE RADist * Milwaukee, WI (1:154/750) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00000 Date: 04/06/97 From: JOHN MUDD Time: 04:52pm \/To: JEFF EDMONSON (Read 4 times) Subj: KW-1 DON'T MEAN TO STICK MY NOSE IN,, (woops, had the cap lock on) try houston amateur radio supply 1-800-471-7373 we need to support the independents, they keep the power houses (aes, hro etc) in line. 73 de kc5gmm john --- Maximus/2 3.01 * Origin: The Politically Incorrect! [OS/2, V34+] (1:106/1010) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00001 Date: 04/05/97 From: FRED MCKENZIE Time: 02:23pm \/To: MARK LETTENBAUER (Read 4 times) Subj: Tri-Band J-Pole Antenna ( In a message dated 03-30-97 MARK LETTENBAUER wrote to ALL: ML> Seems I had problems trying to upload the ASCII file. Apologies for ML> it being incomplete...I'll see if I can figure where I went wrong and ML> try it again in a few days. Mark- I suspect you are viewing the ASCII file using a proportionally spaced font. When viewed with a nono-spaced font (like Courier or Monaco on a Macintosh), it looks good, and appears to be complete. There was only one line near the bottom, that needed two or three spaces to move the characters in line with the rest. 73, Fred, K4DII -> Alice4Mac 2.4.4 E QWK Eval:30Sep95 Origin: Alice strikes back @ --- * Origin: The Bear's Cave Titusville FL 407-383-9372 V34/VFC/H16 (1:374/73) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00002 Date: 04/05/97 From: WAYNE SAROSI Time: 07:53pm \/To: CLAY HARTSOE (Read 4 times) Subj: Messages In a message to Wayne Sarosi <05 Apr 97 1:37> Clay Hartsoe wrote: CH> Wayne, CH> I haven't received any response to the last several messages that CH> I sent you via this echo. The Board I CH> use for email should be back up later CH> today ( Sat ), so hopefully we will have better communications again. CH> The best SWR that I was able to obtain on the antenna was 3:1. CH> I removed four feet of wire, but that increased the SWR slightly. CH> For some reason the dynamics of the antenna is different. I have CH> a feeling that this is due to a larger portion of the wire is being used CH> in the bent portion of the antenna. CH> I'm going to try adding some wire and see what happens.----Clay I'm suprized at the 3:1 SWR, Clay. I got fairly good results with just some left over wire here, no tuner. I sent you a reply to the one you posted here last week but never got a reply to it so I figured you were busy or disconnected again. Let us know what is happening with the antenna. -WS --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00003 Date: 04/05/97 From: WAYNE SAROSI Time: 09:09pm \/To: ALL (Read 4 times) Subj: Our Hale-Bopp Bomb The shot-gun Hale-Bopp poster: He's gone. So let's drop the subject. -WS --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00004 Date: 04/05/97 From: WAYNE SAROSI Time: 09:16pm \/To: ALL (Read 4 times) Subj: Field Day -3a Field Day Antennas & Kits - part 3 Quick set-up modifications for antennas. One of biggest problems during an emergency or field day operations is the assembly and tuning of an antenna. Granted, a whip does not require much in the line of tuning or assembly, however a yagi would. As I recommended before, use antennas that are prepared prior to an emergency or a field day and for emergency use; the simpler the better. Things to keep in mind are that stations outside the emergency area are running at full potential with large directional antennas and full power. Trying to match them while operating in a mud & debris enviroment, out of the back of a car, may be a large undertaking and not practical under the situation. You may have walk in serveral miles carrying 80-lbs of equipment and supplies to reach the emergency site. As for field day, it's much easier. Preps can be made months in advance and it's this one factor that can make or break a field day. ============================================================ Lets look at the Yagi, Cubical Quad, Inverted Vee, and Wire Dipole. These antennas seem to appear at most field days stations I've been to and I've been to several. Keep in mind that a sloper will have similar solutions, which is another antenna I've seen at field day sites. YAGI: (3 Element mono band, HF, armstrong rotor, gamma match) {Use the Cushcraft as a model} Assemble at home per directions. Assemble coax to be used at field day and be sure to provide enough (ie 70-100 ft). Test the coax via a dummy load with 100 watts of power CW. Check the SWR and loss at the desired band for the coax. When complete, save for antenna testing. Place the assembled antenna on a mast or tower for tuning. This height should be the height the antenna is to be used at during field day. I would recommend here that, if possible, test the antenna at the site with the support that is to be used during field day. Adjust the element lengths and gamma match, with the coax tested before, until all the 'kinks' are worked out. The SWR should be less than 1.5:1 across the band area you desire to operate in. Remove the antenna intact and mark the joint fittings of the tapered elements. Mark the dogbone on both the DE and the gamma match element. Disassemble the antenna and store in a PVC 4-in pipe with caps or a wooden box or canvas bag. Coil the coax and cap the PL-259s. Disassemble the mast or tower. Bag the hardware and attach to the support. When Field day or an emergency comes up, you are ready with premarked and pretested equipment. I have done this for six years and have found that it saves a bunch of grief. Use the coax you tested, not some hoser's botch job. And do you own assembly. If it fails, there is no one but you to blame. This concept can take a 2000 point total to a 4000 point level if done right. In an emergency situation, it's the difference between a poor signal and a clear signal. Make it so the tuner is not required. Continued next posting................ :) --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00005 Date: 04/05/97 From: WAYNE SAROSI Time: 09:16pm \/To: ALL (Read 4 times) Subj: Field Day -3b Continued from previous posting: part 3 Cubical Quads: (Mono band, armstrong rotor, etc) This antenna can be a real hoser if not constructed correctly the first time. Preps on this antenna are a must. Spreaders must be checked and elements also. There is nothing worse than getting to the field day site and having difficulty with a Cubical quad. A strong antenna but a real pain in the butt raising and lowering to adjust, especially in the rain. Like a box kite, this antenna does lend itself to the wind. Whether you use the D/DE or DE/R configuration, it makes no difference. This is a homebrew antenna for the most part. There is very little in the commercial source market for these antennas. So, get your sh** together early if you want to use a Cubical quad on field day. Assemble per your design and test per the yagi directions. Cumbersome as it is, this must be done. Mark all connection points and if possible, use expanding spreaders and wire clamps on the ends. IF you use a tuning arm, be sure it's protected in the correct position and can be easily re-adjusted if required. A cubical quad can fold down into a very neat package, but that will take some forethought on your part. ============================================================== Inverted Vees: (fixed, mast support or improvise) An Inverted Vee *may* tune fine at home and then be out to lunch at the Field day site. Using the tuning extentions I posted for Inverted Vees will solve any problems relating to this. Why this happens is that at home the IVee is interacting with Guy wires or other wire antennas or something in the imediate area of the antenna. At my home, the roof flashing does not require a tuner when used as an antenna on 40m. I found this out by accident. Thus, my 40m inverted vee was very difficult to tune. So was a 15m yagi I had once. Solution: I grounded the roof flashing. Select a clear open area to cut, assemble and test the antenna. Once this is accomplished, the IVee should work just fine. Hints: Raise and lower the antenna using a rope and pulley. You can attach a rope & pulley to the mast prior to raising and securing the support. Use rope as guys rather than cable. A wheel & tire from a car make an excellent mast base when combined with a clamp & flange assembly. This appeared in QST I believe about a couple of years ago. Any good mast base will work and I have used plywood and a hinged base support many times. If you can, use a 1:1 BALUN. Hook ups are easier and so is raising. ================================================================= Wire Dipoles: (fixed, mast or rope support) Pretty much like the Inverted Vee, prepare ahead. Similar problems may happen so test in an open area. At the site, determine where the antenna needs to face and then pick out the best supports. If using masts, set up similar to a large volley ball net (very large). The farther apart the supports, the more the rope will sag if no center support is used. On 10m and 15m this is not too much of a problem. By the time you get to 40m and below, the sagging is a big problem. I will suggest the wire dipole be supported in the middle and the ends held out with rope. Set up similar to the Inverted Vee. Use a 1:1 BALUN. ================================================================== -WS --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00006 Date: 04/05/97 From: HOLGER GRANHOLM Time: 03:45pm \/To: CLAY HARTSOE (Read 4 times) Subj: Shutdown Hello Clay, Again I found a message from you in an area that I don't scan. Every morning the conferences I scan are automatically packed and moved to a QWK-packet which I then read and reply to. -> week while the sysop relocates. I haven't received a reply to the last -> message that I sent you, so if you wish to send a message, please post on -> this echo. ---- Later ---- Clay I haven't received anything to reply to. 73 de Sam, OH0NC --- PCBoard (R) v15.22/M 2 * Origin: Coming to you from the Sunny Aland Islands. (2:20/228) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00007 Date: 04/05/97 From: GARY SMITH Time: 10:20am \/To: CLAY HARTSOE (Read 4 times) Subj: Where Are You? Hello Clay, Haven't heard from you in over a week. What's up down there? Did you get the Marconi up? Ttul, tnx es 73 de Gary -k- --- Michiana Mail Center * Origin: CW Technical Support - South Bend, IN - (219) 272-8129 (1:227/129) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E4B00008 Date: 04/05/97 From: JEFF EDMONSON Time: 10:34pm \/To: ROY WITT (Read 4 times) Subj: SWRs & more power DEBATE RW> Don't think that this doesn't happen to the best swr meters. RW> My Bird 43 experiences this as well. Just for grins, insert RW> the meter between the feedline and the antenna, then between RW> the radio and the feedline. Let us know what the different RW> readings are. SWR is actually supposed to be measured at the antenna. A small signal source incjected into the INPUT source of the meter, at the desired frequency will allow instantaneous tuning. Placing the SWR bridge between the radio and say an amplifier will allow you to adjust the input impedance of the amp (if homebrewing an amp) RW> ... It's not bass unless you can feel it! Bass is meant to be felt, not heard! ========================================= 73 = Best Regards ka5thb@bigfoot.com -Jeff KA5THB --- * Origin: A point of The Electronic Avenue (1:387/510.1)