--------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: EE300005 Date: 10/02/97 From: ROY WITT Time: 08:18am \/To: IVY IVERSON (Read 0 times) Subj: High Gain Antennas for 2M Hello Ivy. 01 Oct 97 03:55, Ivy Iverson wrote to Roy Witt: RW>>> You guys are just bound and determined that I go home and look RW>>> through my garage file cabinet...:) II>> II>> Yup. (Pretty please?) }:-> RW>> RW>> See recent post on high-gain omni collinear in HAM-ECHO... II> II> Ok, I'll look in back packets for it. Tnx! If you can't find it, I'll repost.. ... "I suggest a new strategy R2. Let the Wookie win." - C3PO * Origin: KB6PI's Antenna Farm * San Diego, CA (1:202/909.10) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: EE300006 Date: 10/02/97 From: ROY WITT Time: 08:19am \/To: IVY IVERSON (Read 0 times) Subj: antenna thingy Hello Ivy. 01 Oct 97 03:45, Ivy Iverson wrote to Roy Witt: SB>> a radiator? That's what I need to figure out. Don't want to be SB>> cutting up my good coax for nothing! Thanks! RW>> RW>> You'll need a 1/4 wave stub at the top and a decoupling sleeve at RW>> the bottom.. II> II> Quarter wave stub at the top? Are you referring to a whip? No, whips are for Redheads dressed in black leather. Quarter wave stubs are quarter wave stubs as in 1/4 wave antenna... II> And a decoupling sleeve like so?: ||| <-bottom 1/2 wave element ||| ||| -|||- connected to shield here. | ||| | | ||| | <- 1/4 wave metal tube over coax | ||| | | ||| | | ||| | ||| ||| < SO239/Type N connector recommended but ||| is optional. ||| ||| <- Coax to xcvr ||| II> Correct? No, but I corrected it. Slide the tube up and down for best match and solder in place. See part two of the Collinear Antenna in the HAM-ECHO. Maybe by this Sunday. ... Taglines...one line freedom of speech! * Origin: KB6PI's Antenna Farm * San Diego, CA (1:202/909.10) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: EE400000 Date: 10/03/97 From: ROY WITT Time: 09:10am \/To: IVY IVERSON (Read 0 times) Subj: High Gain Antennas for 2M Hello Ivy. 03 Oct 97 00:59, Ivy Iverson wrote to Roy Witt: II>> Ah yes, the good old corner reflector... Now if you were to II>> replace the dipole elements with a 5/8 J-pole and II>> suitably-sized elements, mount them vertically on a boom, II>> (about 6-8 Ft long?), I wonder what ERP you would get with II>> about 40 Watts at the antenna, (50W xmtr)? ... II> RW>>> Build it correctly. Mount it behind the reflector...This is RW>>> about a 7.5dbd antenna with a much better F/B ratio than RW>>> you'll find in a normal Yagi. II> II> (Side view) II> | | | | | | | | | | | | ______________|_____||______|_______|_______|______| R DE D D D D counter | | | | | | weight | | | | | | Pole/Tower leg mount....1/4 wave min ... Unstrap me, damnit, I want to clap too! * Origin: KB6PI's Antenna Farm * San Diego, CA (1:202/909.10) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: EE400001 Date: 10/03/97 From: ROY WITT Time: 09:22am \/To: IVY IVERSON (Read 0 times) Subj: High Gain Antennas for 2M Hello Ivy. 03 Oct 97 00:59, Ivy Iverson wrote to Roy Witt: RW>> provider who couldn't recieve a certain FM station without RW>> interference. I built them a yagi designed for the frequency RW>> of the station and mounted it from the rear with a RW>> counter-balance. A 5 element yagi for 97-100MHz... II> II> There is another way to this, as I learned when I was on the II> engineering staff of a University station in Iowa: II> II> Two cut-to-frequency yagis, one mounted 1/2 wave in front of the II> other, and connected with a 1/2 (or 3/4) wave harness. The rear II> antenna feeds the receiver. (I think I remember this II> correctly). The F/B ratio is almost comeplete, as is the side II> rejection: R DE D D o--o--o--o To RX-/ II> |\ ========|==\==| \| o--o--o--o Well, it got messed up here, but I know what your drawing meant. An interesting concept. This was for rejecting a station off to the side of the reciever and you needed to recieve a station in another direction. You say F/B ratio is almost complete. What does this imply? ... "A phaser is the universal communicator." - Worf * Origin: KB6PI's Antenna Farm * San Diego, CA (1:202/909.10) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: EE400002 Date: 10/03/97 From: ROY WITT Time: 09:28am \/To: IVY IVERSON (Read 0 times) Subj: High Gain Antennas for 2M Hello Ivy. 03 Oct 97 00:59, Ivy Iverson wrote to Roy Witt: II> R DE D D Do you REALLY want a 2M "cannon"? RW>> Nope. I work UHF, exclusively. II> II> AH. No HF either? TS-520 stored in a box since 1985... II>> Have the J-poles paired, above AND below the mast! II>> Also, what difference would it make if the corner had a screen II>> instead of duned reflectors? RW>> RW>> tuned? round? ?? II> II> Rectangular... a classic V-shaped "corner." II> The screen will give you a higher F/B ratio. II>> This would require a non-metallic mast unless it were rear- II>> mounted, but if the DE's were properly phased and everything II>> optimized (resistors in the directors, etc?). RW>> Why would it require a non-metallic mast? Because of the RW>> J-pole? II> II> If the J-poles were vertically arranged both above and below the II> boom... II> II>> .. That just MIGHT be hot enough for moonbounce if it were II>> mounted on AZ-EL rotors! (It would also be about 15 Ft high and II>> quite heavy with a lot of wind resistance!) II> RW>> And more trouble than it's worth...:) II> II> Perhaps... but fun (for me) to contimplate... and it could be II> scaled for any higher frequency. Let me know when you get it working, I'll build one for UHF.. ... Hi, I'm Chip. Micro Chip. Eight-o-three-eighty-six! * Origin: KB6PI's Antenna Farm * San Diego, CA (1:202/909.10) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: EE400003 Date: 10/03/97 From: IVY IVERSON Time: 09:59pm \/To: STEVE BRACK (Read 0 times) Subj: Small AF Amps -=> On 10-01-97 21:27, Steve Brack said to Ivy Iverson,<=- -=>"About Small AF Amps...,"<=- -=> * In a message to Steve Brack on 09-30-97, IVY IVERSON said: Hi, Steve; II> The amp I am referring to was a PC board about 1 1/2 X 3 inches, and you II> could feed a microphone into it, (I used small loudspeakers and output II> transformers connected in reverse), and it would put out a couple of II> watts - plenty to drive 4 speakers in different areas to reasonable II> volume in two buildings. (It was an all-call system which used the II> black-yellow pair in the phone wiring). SB> Well, I haven't seen that item in my store. Sorry. I think RS dropped it over 10 years ago! Just like they did the sensitive little relay used for starting/stopping a casette recorder when a phone is picked up/placed off-hook. I used several of them, including adding a standard phone to a key phone PAX system, (where you have to close an independant pair of contacts to turn on the busy lights in all the other phones). I used another for recording my own phone. But that little relay hasn't been sold by RS for over 10 years. II> But I guess RadShack doesn't think that people actually BUILD things II> any more! SB> Of course, we do! In fact, there are more kits available now SB> than ever before. Our Radio Shack Unlimited in-store catalog SB> carries many kits of various levels of difficulty. Kits... ya, right. "Build 12-15-24-36-however many different things with this kit..." Stuff for cub- and boy-scouts. And you have lots of parts, (but it never seems to be what _I_ need TODAY). Do you have a kit for a BCB-30 MHz receiver that's more than a TOY? I don't mean a 2-3 transistor toy, I mean something that looks and works like a real radio when it's finished? Somehoe I doubt it. Sorry if I'm a little sour on RatShack tonight, I bought something today, (a HTX-404, Cat. No. 10-1140, on close-out that I COULD NOT afford), that has more damn functions in those 24 controls than the whole Space shuttle has in it's cockpit and it's rear flight deck combined! And the 47 page "manual" was NOT written to be understood by a normal HUMANS! (I am no dummy: I have a strong background in electronics, including Chief Engineer of an FM station. I have managed to receive the 3 440 MHz rptrs in the area on it, but can't hit a d___ one of 'em! Yes, the PL is set properly, the offset is set properly, running it off of 12 volts so it should be putting out around 5 watts, set for high power etc etc etc... I KNOW it's transmitting, (I can hear the hum in the stereo and a FS meter shows a potent signal when I key it), but I SHOULD be able to hit at least ONE of those rptrs with NO difficulty on the duck! But after OVER SIX SOLID HOURS of total frustration, I'm getting ZIP! It acts like it's far enough off frequency that it's outside of the repeater's passband. I never would have bought the thing, but I need it for ARES. I bought one HT, (an old 2-channel Motorola), that just was not working out. (Don't ask.) Then yesterday I got the RS flyer that had this thing for $100 off and I got it. I hope I don't continue regreting it, because as it is, there are some utility bills that are going to be late because of it. Sorry, I don't mean to rag on you, but I'm so mad at the thing that I could very cheerfully slam it as hard as I can into the cement retaining wall outside my back door. II> I don't care to etch PC boards unless I have to, (it's messy and the II> chemicals are poisonous and I don't want my cats to get into it)... , but I II> would like to be able to pick up an occasional module, such as a small II> ... (Heck, you can never have too many small AF amps lying around!):-> SB> True enough. 8-) My favorite (in-store) module right now is SB> the IC voice record/playback module. I had a woman install SB> one in her son's teddy bear. Now, every time he pushes its SB> (nose?), mom tells him he's loved. Pretty neat, IMO. Yes, those are cute, but, unless I wanted to build a voice IDer for the radio or a repeater or some similar application, I doubt I have any use for such a toy right now. 73 DE KB9QPM Ivy PS: I just had a contact on 446.000 simplex, so something works. :-} ... "Hailing frequencys are open..." -- ,-----> Ivy's WALL BBS Home of Lakeshore Net <-----, |---------------> Ivy Iverson, KB9QPM <--------------| `-> Netmail me a request for info on Lakeshore Net <-' ___ Blue Wave/QWK v2.20 [NR] --- TriToss (tm) 1.03 - (Unregistered) * Origin: Ivy's WALL BBS - Sheboygan, WI 920-457-9255 (1:154/170) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: EE400004 Date: 10/02/97 From: ROB DENNIS Time: 07:14pm \/To: ALL (Read 0 times) Subj: Some more.... All: As I said some more re-posts of some older stuff that many seem to want again. Most of these articles/posts/ideas were presented here in this echo over the past few years by Wayne Sarosi and many others. All sorts of stuff on antennas,RFI/TVI,mobile setups/noise problems etc. Enjoy the posts and have fun. I am including a header with each posting to identify the authors where they are known to me and to give credit for their work. IF you wish to archive these posts for BBS use do so,if for any commercial CDROM compilation publishing interests please -DO NOT- unless the author gives permission to do so. Anyone who recognizes something they posted and did -not- see their name as the original Author please tell me and I will correct the header-file on your article before re-posting it again. The header will look like this: Original article from: ????? at FIDO or Internet address. Reposted by Rob Dennis,Moderator HAM_TECH,for use of the FIDO HAM_TECH echo. THIS POST/SERIES NOT TO BE USED IN ANY CDROM COMPILATIONS FOR COMMERCIAL SALE WITHOUT EXPRESS WRITTEN PERMISSION OF ORIGINAL AUTHOR(S) OF THIS POST. ALL AND ANY COPYRIGHTS RETAINED BY AUTHOR(S). --- GoldED 2.42.G1219 * Origin: VE3SJN....Moderator....HAM_TECH (1:163/506.4) --------------- FIDO MESSAGE AREA==> TOPIC: 188 HAM TECH Ref: EE400005 Date: 10/02/97 From: ROB DENNIS Time: 07:08pm \/To: ALL (Read 0 times) Subj: VHF-UHF Part 1 Original article from: Wayne Sarosi Reposted by Rob Dennis,Moderator HAM_TECH,for use of the FIDO HAM_TECH echo. THIS POST/SERIES NOT TO BE USED IN ANY CDROM COMPILATIONS FOR COMMERCIAL SALE WITHOUT EXPRESS WRITTEN PERMISSION OF ORIGINAL AUTHOR(S) OF THIS POST. ALL AND ANY COPYRIGHTS RETAINED BY AUTHOR(S). SUBJECT: VHF & UHF Hidden antennas for PUDs/Condos/Apartments These antennas are much easier to hide because of their size. I'll get into some high level design concepts here and expound on them ater. I'll be discussing the following antennas: o Stealth Verticals o Stealth Beams o Indoor Antennas o Indoor/Outdoor use of Mobile Antennas o Field Day / Portable --------------------------------------------------------------- Stealth Verticals: This type of VHF / UHF antenna is very popular with amateurs. The are easy o build and install. Many commercial antennas are available,but for the dollar, an amateur can build a superior VHF or UHF antenna for the base or mobile se. For the PUD/Condo/Apartment user,even a simple vertical can be a major problem to install. Location in an apartment may be one of the biggest problems facing an mateur when antennas are prohibited. There are large multi-element verticals on the market such as those made by Comet and Diamond. The size of these antennas makes these a bit more ifficult to install. There are other homebrew antennas that can be installed however. These antennas will be discussed here. J-Pole: The J-Pole is an exceptionally good antenna and easy to build if the directions in the ARRL handbook are followed correctly. One modification I recomend for the J-Pole is to solder the tuning connections after the SWR is set. This allows for 'no maintenance' on the J-pole and no surprizes with SWR changes due to corrosion. 1/4, 3/4 wave ground planes: These ground planes offer unity and 3dB respecfully. These antennas do not need coils or tuning circuits to accomplish their action. Discones: This antenna can be homebrewed or bought commercially. The discone is an excellent antenna, but has it's drawbacks in hiding. The antenna has unity gain and can be used on multiple bands. Vertical Dipole: This antenna can be put together in various configurations with various matching devices. The dipole is a halfwave. Full Wave Loop: This antenna can be configured to vertical polarization. It is not omni, but exhibits good gain in a bidirectional pattern. There are many more antennas that exist. Some are larger,some don't have the bandwidth, and still others require coils & capacitors to make them work. The aboved mentioned antennas are easy to homebrew and make for good ntennas that can be used by PUD / Condo / Apartment dwellers. All the above antennas are in the ARRL antenna book. The design and construction of these antennas s easy if the directions are followed in the book. What I intend to accomplish here is placing the antennas such that they go unseen by all.