|------------------------------------------- Copper tape This folding method insures good contact on more than one surface. One warning, do not leave air gaps as it will have a capacitive effect. Solder doesn't stick to Aluminum foil very well. With enough heat, you can solder anything. Too bad the aluminum foil won't hold up at that temperature and neither will the solder. You now can solder leads to the BALUN or solder the coax direct to the copper tape. For an indoor antenna, the foil antenna works rather well. It can out perform a vertical and pull in the weak ones with ease. I think you'll find it one of the most inexpensive antennas you can build yourself. 73, Wayne, KB4YLY --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3U00003 Date: 03/23/97 From: WAYNE SAROSI Time: 08:10pm \/To: ALL (Read 3 times) Subj: Indoor Antennas-3 SUBJECT: Indoor antennas, VHF/UHF Discones The discone antenna is a rather unique antenna for VHF and UHF. The discone has no gain to speak of, yet can provide the user with a range of ten times the design frequnecy for reception and transmitions. This means that a discone designed at 140 MHz will work fine up to 1.4 Ghz. Hiding the discone outside may prove to be quite a feat. Unlike most antennas, the discone has a large skirt and is tall to boot. It's shape can draw attention. If you can place the antenna outside, it will give you excellent coverage over it's range. Inside, the discone works well minus the attenuation caused by the building it's in. There are many Discones available on the market if you choose not to build one. Building one can be fun if you take the time and lay everything out ahead of time. There are a couple items I would like to point out about discones. 1) The gap between the top-hat and the skirt is critical. 2) The area under the skirt is a null to the antenna. Design parameters are easy. o The top-hat diameter is: (0.1778 * (984/f MHz))*12 EX: at 140 MHz --> (0.1778 * (984/140))*12) = 15-in o The diameter of the skirt, at the base, equals the length of the skirt elements. This gives the user the closest impedance to 50-ohms. Thus a skirt element length is: (0.2675 * (984/f MHz))*12) EX: at 140 MHz --> (0.2675 * (984/140))*12) = 22.56-in o The gap is: (0.007114 * (984/f MHz))*12) EX: at 140 MHz --> (0.007114 * (984/140))*12) = 0.6-in A tin funnel works well as a starting base that brass skirt elements can be soldered to. An SO-239 chasis connector can be fit into the cutoff funnel end and the top-hat soldered to the center pin of the SO-239. Insullating spacers can be used to strengthen the gap. I've used a brass screw that was soldered between the center pin and the top-hat, but you can use anything that you can solder. I have a motorized discone in works. The stepping motor will be incorporated to change the gap, to match the frequency, for best SWR. -WS --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3U00004 Date: 03/23/97 From: WAYNE SAROSI Time: 08:13pm \/To: ALL (Read 3 times) Subj: Indoor Antennas-4 SUBJECT: Wire beams, indoor antennas For many of us, the antenna is the biggest problem for most hams. Hams have to contend with neighbors and the XYL in order to pursue their hobby. An interesting HF and VHF idea I've seen used is the wire beam. The wire beam is unrolled and suspended in the direction required for operation. After the operation is complete, the wire beam is rolled up and stored for the next time. This type of beam is excellent for 10m and up to 1.25 m. You may be able to set up a wire beam for frequencies below 10m if you have the space to do so. This antenna is also excellent for suspension in an attic. A simple model is shown below: R DE D -----------||--|-------------|----------|--||----------- || | | | || || | | | || || | | | || -----------||--|-------------|----------|--||----------- || | | | || || | | | || || | | | || -----------||--|-------------|----------|--||----------- Aside from the elements, the rest of the configuration is non- conductive. Wooden dowel supports are outside the ends of the antenna and string/rope can be used to support the elements. The wooden dowels are not required if suspension is taught. You can see that variations of this set-up can be incorporated to accommodate most any frequency from 10 to 1.25 meters. -WS --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3U00005 Date: 03/24/97 From: WAYNE SAROSI Time: 07:09pm \/To: RAY WADE (Read 3 times) Subj: Check In a message to Wayne Sarosi <23 Mar 97 14:32> Ray Wade wrote: RW> FYI Wayne. Banks consider any check that is less than 6 months old RW> (since written) to be "fresh", unless the check says something to the RW> effect of "good until" on it (like some "rebate" checks do). No problem, they cashed it. TNX Hope the plans were to your liking. -WS --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3U00006 Date: 03/24/97 From: WAYNE SAROSI Time: 08:22pm \/To: STAN BLACK (Read 3 times) Subj: homebrew yagi In a message to All <24 Mar 97 0:05> Stan Black wrote: SB> Hi! Thanks for reading this! I am SB> converting an old avanti "moonraker" beam SB> to 10 meters. I have eliminated the vertical elements and just left the SB> horizontal ones. Here's the spacing and lengths of the elements. SB> length (ft) SB> reflector 17.0 SB> driven 16.5 SB> dir 1 16.0 SB> dir 2 15.5 SB> spacing (ft) SB> RE-DE 5.0 SB> DE-D1 5.0 SB> D1-D2 5.6 Those sound close enough to work OK. SB> The problem is that no matter how I tweak SB> the gamma match, I can't get the swr SB> below about 5:1 at 28.4mhz...I've cleaned and checked all connections. SB> It seems to be resonate at 29.02mhz and 26.04mhz...I checked it with an SB> MFJ-259 swr analyzer. SB> I think I need a longer gamma match. The SB> old one has a center rod of about 24 SB> inches slid inside a larger tube that's about 9 inches long. SB> Any suggestions?? I am tired of climbing SB> the tower!! Thanks for reading this SB> message and 73 de Stan Black KC5BFA I would go with a length of RG-8 Foam, strip back the outer casing, and shield. Just use the foam dielectric and a thin walled length of 3/8 inch aluminum tubing. Spacing from the boom would be 5 to 7 inches. the length of the gamma would be 30 to 33 inches. Be sure you can slide the dielectric inside the tubing before you by it. If you need some RG-8 foam (enough for the gamma) and can't find it anywhere, drop me a line with your address and I'll send you some. -WS --- XRS! 4.50+ * Origin: KB4YLY, Moderator (1:374/73.2) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3V00000 Date: 03/23/97 From: CHARLES MOODY Time: 06:39pm \/To: STAN BLACK (Read 3 times) Subj: Re: My first J-pole SB>Hi Charles! If you will make your cuts about 60" on the long leg, you will SB>flatten out the curve. I also added a brass bolt on the 19" piece. That ............................................................................ That is what I thought. I have also heard of people using brass bolts to fine tune things, but I did not know you put it on the 19" piece!? I thought it would be the long part since that is the part that the transmission is on. Maybe in simple terms you could explain that to me so I can better understand. ............................................................................ SB>Next you may want to try a double j-pole!! I'm going to!! Hope this helps. SB>de Stan kc5bfa ............................................................................ Double J-pole what does that look like? This or This Or other...? | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |__|__| |__|__| | | | | | | | | Thanks 73 Chuck Kb0RVD * OLX 2.2 * Right now time is having it's way with you..... --- WILDMAIL!/WC v4.12 * Origin: Daedalus Online, Minot ND (701)857-6090 (1:14/648.0) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3V00001 Date: 03/25/97 From: STAN BLACK Time: 11:55am \/To: WAYNE SAROSI (Read 3 times) Subj: Re: homebrew yagi Hi Wayne! Thanks for the dimensions on the gamma match! I have the tubing and the rg-8 foam. I'll build it today! Of course, I won't install it, cause we had a cold front blow through West Texas last night. Brrrrrr! It will problably be 80 tomorrow!! :-) Thanks again! de Stan KC5BFA --- GEcho/386 1.11+ * Origin: Great Beta Video System For Sale, Includes Movie (1:392/11) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3V00002 Date: 03/24/97 From: DENNIS WREN Time: 11:26pm \/To: MARK MAGILL (Read 3 times) Subj: Icom Batteries > Some have told me that rapid-charging shortens > the life of the pack as opposed to the long-cycle > rates. Any truth to that in your experience? Or other > pros/cons one should know about the different rates? I have a Periphex BP8S that I use on an Icom 02at. It is 9 years old and is always rapid charged in an Icom charger. --- * Origin: A Point of N4SDI - Titusville, FL (1:374/73.1) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3V00003 Date: 03/24/97 From: DENNIS WREN Time: 11:31pm \/To: FRED MCKENZIE (Read 3 times) Subj: Icom Batteries > Battery packs that are intended for rapid > charging, are supposedly constructed to withstand the > higher temperatures. As such, they will probably hold > up better than a slow-charge battery being charged at > a high rate. I agree that such a battery would > probably last a little longer if charged correctly at > a lower current, but it is the price you pay for the > convenience of fast charging. I have a 9 year old Periphex BP8S 1200ma battery that was built for rapid charge only. When I got it there was no way to hook up a slow charger to it, they latter made an adapter to allow the slow charge hookup. I use an Icom charger and the battery is still going strong. --- * Origin: A Point of N4SDI - Titusville, FL (1:374/73.1) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: E3V00004 Date: 03/25/97 From: EDWIN OLAVARRIA Time: 09:47am \/To: ALL (Read 3 times) Subj: AZDEN PCS-2000 Does anyone have the manuals or diagrams to this radio, I have one of these and would very much like to use it for packet but the radio is not feeling well at all. It seems that when I transmit it sends the signal but I have no mod, I have looked at the mike and replaced the mike element but still have the same problem. I have a few people that are willing to work on the radio but no one has the diagrams for it. Thanks to all in advanced. Edwin de N3YKL --- DB A3000gb/005204 * Origin: The Image Of Man Systems , N3YKL (1:2607/108)