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  • K6CPO's Avatar
    Today, 00:15
    That's basically what I did, except that I added sheet metal to both sides and then put barrel connectors through the wood and metal. I also added screw-on caps for weather proofing of unused connectors.
    8 replies | 272 view(s)
  • w0ecs's Avatar
    Yesterday, 23:49
    w0ecs replied to a thread 160m "T" vertical antenna in Antennas
    Thanks Jon The 160m antenna I'm putting up is considered to be a vertical. it consists of a 58' horizontal wire up 82' which performs as a non-radiating capacitance hat. A 82' long wire is attached between the center of the horizontal wire and ground level. This antenna is described in wikipedia as T-Antenna and contains a very good description and history. I am, of course, very partial to open wire feedline - but I didn't want to mess around with a balun since the expected impedance is somewhat lower than 52 ohms - close to matching coax. Also, I hadn't heard of vertical antennas fed with anything but coax. So I wasn't contemplating sharing feedlines with my doublets for sure - they work great and I'm not going to mess with them - especially with the Bouvet expedition looming. The main thing I would like to know is whether or not burying the coax feedline really eliminates the need for a current choke balun. BTW - great quip
    2 replies | 74 view(s)
  • John_D's Avatar
    Yesterday, 22:50
    John_D replied to a thread 160m "T" vertical antenna in Antennas
    hi Frank (w0ecs) I see from your QRZ.com page that you use open wire feeder for those dipoles ....excellent! I am a firm believer in that type of feeder and avoid coax if at all possible. It would help with your question if you can put some sort of diagram onto the forum. When you mention the vertical as being 82 feet long, is that a single wire or is it twin feeder? Coax feeder was only adopted post war as it was readily available due to its use with TVs. Until then open wire feeders, which are really great as they offer phase/anti-phase feed, or single wire feeds were the norm. VSWR was only invented later LOL. BTW, have you thought about feeding those dipoles you show on your page, with the same feeder?
    2 replies | 74 view(s)
  • Obed's Avatar
    Yesterday, 21:45
    Obed replied to a thread Hustler 5BTV in Antennas
    your experience of local vs DX is the same as mine was.... horizontal dipole worked better on local ragchew than the vertical did, and the vertical out performed the horizontal dipole with DX work...congrats, go snag some paper.
    8 replies | 260 view(s)
  • flboy's Avatar
    Yesterday, 21:28
    flboy replied to a thread Hustler 5BTV in Antennas
    I used the DX Engineering plate as you can see in the above pics.. I have about 20 radials in and a 10' copper clad ground rod down at the base which is surely into our high ground water table here in Fl. The 5BTV has less noise and slightly better reception the my OCF dipole that is up 30ft. I am also getting 58/59 signal reports all over North and South America, Carribean, and Western Europe and Eastern Europe from Central Florida on 100w. Based on that and the omnidirection over the OCF Dipole, it seems to be a better antenna... just alot more effort and expense to install. There are diminishing returns on radials after you get to that critical mass. I think I found it my particular environment with burried radials. I have less than 2:1 SWR across all bands except 80m with 20m and 40m at less than 1.5 without the tuner . I know that does not equal transmit efficiency per se, but contributes significantly. So far, very happy with the results. Would a few more radials improve it even more?...
    8 replies | 260 view(s)
  • pmh's Avatar
    Yesterday, 19:58
    Plenty of info on ballons from the enthusiasts on Twitter. You can also use ALC to reduce your 1W further. My tuner has digital power readout, so quite easy for me to do. 500mW does seem the threshold for me. Above sort of guaranteed Australia, below is condition dependant. You can also copy the data base page, after filtering out specific callsigns, and then paste this data into excel. You can then see the changes in SNR throughout the day. Kind regards,
    4 replies | 191 view(s)
  • G0NMY's Avatar
    Yesterday, 19:55
    G0NMY replied to a thread QRP transceiver kits in Amateur Radios
    Yes the Bitx40 and uBitx are nice radios although they arent really kits as such they come ready built you just have to connect them all together by adding harware and case. What we should really ask you is what is your experience at building and soldering? If you know how to solder and what the different components are then any kit will fit the bill. However if you have never built a kit before then I would recommend you getting one of the cheap Chinese kits for a few dollars as previously stated above. That way if it doesnt work first time and you cant get it going then youve only lost a few Dollars/Pounds and you will gain valuable experience in the process. If you know your way around components and can solder well. I would reccommend the qrp-labs QCX transciever. Why? because once built it has built in tools to help to acurately Set up and align it. and it has a built in Morse Decoder and can transmit a WSPR Beacon. And the BIG plus the documentation is excellent! Ofcourse there are other kits out...
    7 replies | 200 view(s)
  • w0ecs's Avatar
    Yesterday, 18:20
    I've finally cleared space in the woods for my 160m T antenna - It will have a 58' topwire and 82' vertical wire with approx 100' of coax to the shack. Two questions: * This may be a pretty decent antenna on other bands with the help of a tuner - therefore, shouldn't I use as low loss as possible coax since off band swr will probably be high? * Davis RF mentioned that burying the coax would eliminate the necessity of a current choke balun - is that really so? thanks, w0ecs
    2 replies | 74 view(s)
  • Obed's Avatar
    Yesterday, 17:03
    2511382 you do not say where you are located, if you are in the states.... the materials Paulears listed can be obtained at electrical supply houses and most of the larger home improvement stores... and if you have any old fashioned hardware stores in your area they often have it as well. Lots of online sources can be found with a google search.
    7 replies | 225 view(s)
  • paulears's Avatar
    Yesterday, 16:56
    The Denso tape is very similar to the stuff plumber use to seal around leaky waste pipes and is truly disgusting stuff. It's mega slimy and sticky, and sticks to you, and you stick to everything. Getting it on clothes is a nightmare. After exposure to the air, the dust settles and the stickiness goes away on the outside, but reappears when you cut it off. Self-amalgamating tape can be obtained from loads of on-line sources, and if you've never used this stuff it is brilliant. Pull the backing off the rubber tape, stretch to twice the length and wrap around the cable and connector, overlapping each turn and in a couple of days, it's one solid lump. I'm quite happy to just use this on my own antennas - and it wears quite well lower down, not exposed to mega winds, temperatures and sunlight.
    7 replies | 225 view(s)
  • 2511382's Avatar
    Yesterday, 14:54
    I didn't mean to have Chris install it. Chris sent it to me, and I had a local electrician install it. It took all of an hour and a half, and only cost me $150. Worth every penny! (to me anyway...)
    8 replies | 272 view(s)
  • dtrewren's Avatar
    Yesterday, 09:21
    Excellent - thanks for the feedback guys ! I will give it another go at lower power - the FT-450D has 1W steps 1-100W so I will turn it right down. I also currently have about 60m of RG213 to the feed point on the antenna so that is going to equate to ~1.5dB loss the antenna match is quite good on 20m. I quite like the idea of building a lightweight beacon and then sending it up on a tethered balloon - a summer project I think :) Not sure what the rules are on launching low power radio beacons .... 73's,
    4 replies | 191 view(s)
  • WZ7U's Avatar
    Yesterday, 07:51
    Somehow, I doubt Chris is going to go to the UK for an install. But I bet he would send one that way.
    8 replies | 272 view(s)
  • John_D's Avatar
    Yesterday, 00:29
    Hi Dave, 10 watts is a bit QRO for WSPR although it is available as the maximum in the TX side of the program. (30dbm). I would suggest 2w maximum. This represents 33dbm in the WSPR Options. The receive side of programs designed by Joe Taylor, e.g. the JT series etc, are essentially very sensitive pre-amp broadband circuits. What happens when they receive a strong signal is that they de-sensitive (get swamped) the RX and only that signal gets through, meaning that the weaker ones do not get heard and cannot be decoded.
    4 replies | 191 view(s)
  • pmh's Avatar
    Wed 17th Jan 2018, 23:38
    17001km on 380mW is my record. I usually stay around 500mW, but have picked up a 2W linear to play with for my portable beacon. Kind regards, Phil
    4 replies | 191 view(s)
  • dtrewren's Avatar
    Wed 17th Jan 2018, 21:12
    Evening all, I had my first play with WSPR last night having previously been into JT65 and FT8. I set my Yaesu FT-450D up to 10W on 20m and performed a couple of transmissions. After a minute or two popped the wsprnet map up .... only hit the Neumayer Station in Antarctica range 13588km (8152 miles), plus another station in south Africa. See attached .... I went to the pub a little bit chuffed :)
    4 replies | 191 view(s)
  • 2511382's Avatar
    Wed 17th Jan 2018, 20:19
    2511382 replied to a thread End Fed Or Inverted L in Antennas
    The following is my opinion only---- Personally, I would use that balun as indicated in the top picture. Does that balun have a ground connector on it? A previous post talked about a 100' counterpoise wire, and I would suggest using that as well. I would avoid trying to use the coax as a counterpoise, as you may introduce RF in the shack, and in fact I would recommend purchasing a common mode choke (www.myantennas.com) to avoid this, and run a counterpoise wire. Have fun! '73, 2511382
    3 replies | 319 view(s)
  • 2511382's Avatar
    Wed 17th Jan 2018, 19:51
    I thought I was doing a good job filling the connector with "stuff" dielectric compound, and wrapping it with coax-seal.... It seems to keep things clean, but you never know for sure, and your suggestion seems a whole lot better- Where do you get that stuff? links to the product page? Thanks in advance!! '73, 2511382
    7 replies | 225 view(s)
  • 2511382's Avatar
    Wed 17th Jan 2018, 19:47
    2511382 replied to a thread New to HF in Antennas
    I have used PAR END FEDZ with a lot of success- These are end fed wire antennas that perform well for what they are. www.lnrprecision.com I also recently purchased a Myantennas 10-80 antenna, and I have been having great success with it- 10-80 meters with no tuner! (well ok-- except for portions of 80).... It's the best, simplest thing I've found, and may suit you well at your location. www.myantennas.com I've also heard good things about the MFJ Cobweb antenna- I don't know anything about it though- It's also not portable, and it doesn't go below 20 meters- AND well...it's MFJ--- Mighty fine Junk....
    10 replies | 506 view(s)
  • 2511382's Avatar
    Wed 17th Jan 2018, 19:42
    I just had one of these installed at my QTH, and it is absolutely fantastic! www.kf7p.com Chris is outstanding- excellent to do business with. You end up with a completely sealed box on the outside of your house, and the coax runs through a 3 inch hole into your shack. IMO, there is no better solution! '73, 2511382
    8 replies | 272 view(s)
  • 2511382's Avatar
    Wed 17th Jan 2018, 18:52
    2511382 replied to a thread Hustler 5BTV in Antennas
    Hello, I have a BTV-5, but I have since taken it down. Unless your tuned radials are elevated, you need a lot more than a few for each band. That is, if they are buried, you need at least 60, cut a 1/4 wavelength on the lowest band you are going to use. The antenna will receive without them, but it will not transmit very well. I had 25 buried radials, and my dipoles performed better on every single band, even at a low height of 40 feet-- (on 80 no less!) The BTV-5 from what I hear is the best for DX on 40 meters, due to the low angle of radiation put out by the antenna being vertical. You have a very nice looking setup, and from your picture it looks like it would be easy for you to add 60+ radials down. I would recommend the DX Engineering grounding plate- www.dxengineering.com It will allow you to easily do this. Let me know how it works. '73, 2511382
    8 replies | 260 view(s)
  • Brundizzle's Avatar
    Wed 17th Jan 2018, 18:45
    Thanks for the reply Paul. good to know that the connection shouldn't impact the set up. I am sure I can cut the length accurately. As for the velocity factor, I will have to reply on the specs from the manufacturer (I have no antenna analyser) .. the thing is.. i read conflicting info on these kind of antenna's .. people who claim much better receptions and people who say it didn't work ... as I only have a small en very cheap 144/430mHz whip antenna, I suppose bending a paper clip the right way would increase my reception :welcoming: I googled "pvc and antennas" and found a lengthy thread about the use of pvc.. apparently is has to do with dielectric constant of the pvc.. the thickness of the pvc ..etc etc.. anyway... gonna give it a go :)
    6 replies | 152 view(s)
  • Brundizzle's Avatar
    Wed 17th Jan 2018, 18:10
    Yep, part A is coax as well. I was thinking of making it either 1/4 or 1/2 wavelength ... but as part A is connected core to core / shield to shield to the coax cable leading to the SDR dongle, I gathered it wouldn' t make difference ... but I am not sure :uncomfortableness: Reason not to run the coax straight out: this is not a permanent antenna... so i want to be able to take it off easily and not have an antenna with 4 to 5 meters coax attached to it.
    6 replies | 152 view(s)
  • paulears's Avatar
    Wed 17th Jan 2018, 17:11
    That section is 50 Ohm feeder, and the addition of the make and female connector doesn't have an impact. You've decided to make a rather complicated antenna though. I spent ages making one of these for UHF (around 453MHz) and the big problem I found was simply cutting each section accurately enough with a very small gap between, just big enough for the soldering iron. Out of the plastic it worked quite well but didn't like the plastic sleeve at all which on the analyser, detuned it quite a bit. The frequency dropped quite a bit, and without the analyser, the gain wouldn't have been as planned. The grey plastic pipe is much worse, I suspect some of the stuff used to dye it grey causes the problem? These stacked sleeves dipoles should be very good gain wise - but none of the ones I built worked that well - I guess I just wasn't accurate enough in my measurements. At 1GHz plus - you need to be even better.
    6 replies | 152 view(s)
  • Sudden's Avatar
    Wed 17th Jan 2018, 16:44
    Try a close call scanner next to it and see what the frequency is.
    2 replies | 106 view(s)
  • 5B4AJB's Avatar
    Wed 17th Jan 2018, 12:30
    It's probably just missing the first few digits, so, you'd be tuned to 7.91010 (or similar, not sure of the coverage)...
    2 replies | 106 view(s)
  • 5B4AJB's Avatar
    Wed 17th Jan 2018, 12:27
    Part A is coax, right? Maybe you should be looking at fraction of wavelengths of the operating frequency. Part of me says not to bother with that, why don't you do away with the connector altogether and just run the coax straight out...
    6 replies | 152 view(s)
  • Noisewerx's Avatar
    Wed 17th Jan 2018, 09:15
    Hello all Just picked up 101ZD Allworks fine but when i select 40 metres digital read says 91.100meg The same as v when you put it on aux Can anyone help or have any ideas Cheers
    2 replies | 106 view(s)
  • Brundizzle's Avatar
    Wed 17th Jan 2018, 08:12
    Hi John, thanks for your reply. Using a SDR Dongle and the right software is enough to receive and decode the ADS-B signal on a normal laptop/desktop/rpi. I am pretty sure teh signal can be picked up with different type of antennas as well, but from searching the available content on the internet (that I could find), people seem to get quite good results from a CoCo. As I basically know nothing about antenna's I decided to follow that advice :joyous: So I got all materials I need.. and just got confused about above mentioned issue :joyous: cheers, Bruno
    6 replies | 152 view(s)
  • John_D's Avatar
    Tue 16th Jan 2018, 23:06
    Not sure which wireless you have but I thought that ADS-B aircraft broadcasts required a dedicared 1090Mhz rig. For that frequency a simple vertical plus radials would suffice, fed by low loss coax.
    6 replies | 152 view(s)
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