I know, it's an old thread, but maybe this will help someone anyway (these old threads *do* come up in searches). Here's where I just downloaded the Operator's Manual with Schematic for a FT-530:

http://www.radioamateur.eu/schemi/FT530_user.pdf

And yes, it's in English.

Thanks, Dave. So I was calculating correctly. Hmmm... that means W1AW was doing it wrong? oops!

(oops... I meant to say I started by tuning my radio to 18.1015 and looking at 1000 on waterfall for 18.1025...)

I had been under the impression that the operating frequency would be the radio's dial frequency (assuming your radio is displaying actual frequency, rather than a built-in display offset) plus the audio frequency (point on the waterfall) at which your software is operating.

However, When I went to copy the W1AW FD bulletin, I tuned to the announced frequency of 18.1025 (as 17m seemed my best bet) by setting my radio to 18.10125 and looking at the 1000hz point on my waterfall. In the few minutes before the scheduled transmission, I saw several people tuning up at that same spot, so they obviously had the same idea as I.

However, the actual transmission occured further up the dial, at approx. 18.1025 + 1500 (radio on 18.1025 and 1500 on the waterfall) or 18.104.

So, which is the correct way to specify a PSK31 operating frequency???

I have the Linux version, and, as it ships, it will run fldigi, though a few hacks are needed to be able to install and run it (or, for that matter any additional software) on the "Linpus" distro it comes with. Also, you have to use the built-in audio. A USB audio interface will not work as the distro contains no support for USB audio and no way (that I could find) to add it.

HOWEVER... I upgraded mine to Ubuntu, and I easily use fldigi and my SignaLink USB - works quite nicely.

The AAO, FT817, and wire antenna or MP1 will all fit in a single briefcase for a very portable digital station!

I was thinking a good option for VHF and/or UHF on a motorcycle (or even a bicycle) might be to find or devise some method of mounting a HT in a position that would be both easy to operate (tho even that isn't critical if you tend to hang out on just one frequency) and a decent antenna location, and then use one of the longer whips that will mount directly on the BNC connector on top of the radio. If the mount is such that the radio can be easily detached, then it can be removed to avoid theft or for off-bike pedestrian use.

I've not looked, but I wouldn't be surprised if there are such mounts commercially available. If not, one of the mounts designed for cellphones or GPS might be adaptable too.

Not sure if what I am experiencing is unusual or not, but it seems so to me.

It would be my understanding that any antenna will have some frequency at which it is reasonant, and at that point the reflected power should be nothing, or nearly so, giving an almost perfect SWR. Even if the antenna is affected by nearby objects, that would merely change the radiation pattern and reasonant frequency, but a perfect match should still be had at some frequency, no?

Here's the antenna and possible environmental complications:

It's a simple 1/2-wave 6-meter dipole, horizontally mounted. Fed by 50 ohm coax (brand new RG8XII, so I should be able to rule out coax defects or contaminated core). The elements are made of 1/4" copper tubing attached to a piece of wood as an insulator/mounting point. It is at the top of a 6-foot steel mast (feed point is actually centered over the top of the mast). There is one other nearby object in addition to the mast that may be affecting it... there is a cooler (about a 3x3x3 foot cube of sheet metal) within 1/4 wavelength of the "ground" leg of the dipole. Granted, not ideal, but I would still assume I'd be able to get a near-perfect SWR out of it at some frequency, but instead...

Here's what is going on:

After pruning (and over-pruning and adding copper wire back to the ends) the best I am able to achieve is about a 1.2:1 SWR (at about 52MHz). As I change frequency in either direction, the SWR goes up, but doesn't seem to get worse than about 1.5:1 at either end of the band. While many people will say "so what's the problem - 1.2 is great and anything under 2:1 is OK" I'm still curious as to why there isn't one point at which it is near perfect.

This is actually a two-part issue. First of all, can a second sound card be installed? That will depend somewhat on your system, what sound cards you choose, how much other hardware is installed, and if you have the needed resources (IRQ, DMA channel, etc.) available. If you are using any reasonably modern PC and at least one of the sound cards is a PCI card, the answer to that is probably yes.

The second part is whether or not it will do what you want to do (operate PSK31 and play MP3s simultaneously). That will depend alot on how powerful your computer is (especially CPU speed) and how many other tasks you are also running (email, web browser, web cams, whatever). Hopefully someone else who has successfully done what you want to do will chime in here with an authoritative answer, as I can only make educated guesses based on my computer experience. Decoding PSK31 and playing MP3s are both fairly CPU-intensive. I'd say if you have about 300MHz of processor speed for each of these, you will probably be OK. In other words, if you have a 600MHz or faster system, you'll be able to do them simultaneously.


 - Mike KD7TKQ

As usual, lots of good advice. I'm so glad I found eHam.net

Thanks to all for reminding me of the safety aspects of grounding. I live in Phoenix, where electrical storms are a relatively rare occurance, in an urban area, surrounded within a few hundred yards by plenty of taller and more likely targets, so a direct lightning strike is at the bottom of my least of potential threats. Especially sincy my antennas, at least to start out, will probably be less than 20-30 feet above ground. Induced currents from a nearby strike, however could be a credible threat during our occasional storms.

I knew not to use gas lines as a ground, but I hadn't considered the possibility of water lines unsoldering themselves - I suppose that's very possible though, in the event of a direct strike. WOW.

That Polyphaser website is a treasure-trove of great info about grounding and lightning protection. They even have a document specifically about ham radio stations, treating the situation with every bit as much seriousness and professionality as if it were a commercial broadcast installation.

While safety should be a primary consideration (and thanks again to all for pointing that out) I was also concerned about how the ground, and in particular, the routing and length of the ground line from the station to actual ground, affects antenna system performance. If I plan to use coax-fed dipoles, is this a non-issue?

 - Mike, KD7TKQ

I imagine the importance of a good and proper ground varies somewhat relative to the type of antenna used and the frequency involved, but in any case a good ground is always better than none. My shack is on an ouside wall, so I could do a ground rod, but I am in Arizona and I understand that's not always a good solution here because of the dryness and type of soil. I'm also right next to the bathroom, and the house has copper water pipes, so that might be a good choice. My only concern is that the pipes run overhead in the attic (single story house, cement slab foundation) and there's probably about 60-75 feet of pipe before it  goes into the actual ground. Another option would be for me to run a wire (probably about 50 feet) around the outside of the house to the point where the water line goes into the ground. The possible advantage to this over using the convenient water pipe would be that my ground path would be lower to the ground and farther away from my antennas versus the overhead attic path of the water pipes. Would that matter? Oh... using the electrical ground is out - the house is too old; everything is 2-wire (actually someone "updated" it with 3-prong recepticles, but the ground prongs are not connected!). Besides, even if they were grounded, the wiring takes the same overhead attic path as the water pipes.

So... would there be a difference between using the overhead water pipes versus a wire at ground level? If desired bands make a difference, I hope to be able to work everything down to at least 80 meters (If you've checked my call you'll notice that I'm just a newly licensed technician, but I plan to upgrade and work HF and want to do this right in the first place rather than have to do it over again later). I will probably be using dipoles or other balanced antennae fed via coax, but I'd also be interested in knowing the effect of different ground paths on other types of antennas and feed lines.

 - Mike, KD7TKQ

Thanks to all who have replied. I'm definitely learning some new things, and being reminded of some stuff I'd long since forgotten (I'm new as a ham, but used to do CB and other radio stuff many many years ago, and have been into radio and electronics of one form or another all my life).

To the folks who suggested a vertical ground-plane style antenna - that's a good option, but I didn't consider it at the time because I was trying to throw something together with just what I had on hand, and I didn't have anything stiff enough to be self-supporting. Hmmm... maybe coat-hangers? Also... if I were to make that type antenna, would it also be usable for UHF (440)? Without making some sort of coil/trap halfway up the radiator?

Good point about the feedline having to lead off at a right angle to the antenna. I figured that might matter, but didn't think it was too important. I have it coming off at a right angle, but only for a couple inches, then just droops down naturally.  I did see something on the web about making a vertical dipole out of coax by stripping the outer sheath the appropriate length, then turning the shield inside-out to make the lower element, while the now-exposed center conductor becomes the upper. The author's intent was a handy portable antenna (make a small loop in the end to hang it from) but I could just as easily staple that to my board up on the roof.

Someone asked if this is my first homebrew antenna. Almost. It is my first homebrew ham antenna. I've played with various wire antennas in the past, mostly for SW reception, and a little for FM broadcast. And this would be my second "serious" antenna for transmitting. About 15-20 years ago I had some sort of mobile telephone system I'd picked up somewhere. Most likely intended for European market. It amounted to a 10- or 20-watt cordless phone - base transciever connected to phone line, and portable unit was about the size of the early "transportable" cell phones. It was pretty cool - full duplex, ringing and dialing, etc. But I ramble. I'm assuming it was not intended for this country becuase it worked around 70 MHz - really ripped up TV channel 4 (vacant in this area tho). In retrospect, I imagine it was totally illegal. But anyway, I built a vertical antenna for that - five stiff wires on an SO-239 - one soldered to the center, and four radials, one soldered to each of the four holes where the chassis screws would go. The antenna went up in the attic of the two-story apartment building I was living in at the time. Actually worked OK... lack of height was my biggest problem. I could hit it from 20 miles away or so if I was up on a hill or even a high freeway overpass.

Again I ramble  Mostly wanted to say thanks to all who responded. Thanks for the info and thanks for the encouragement. I definitely intend to experiment more and build more antennas.

- Mike, KD7TKQ

Of course, Russ, that's probably it! FOr some reason I'd thought the natural impedance of a dipole was 50, not 75 ohms at reasonance. That being the case, I suppose a 1.5:1 balun would be the ideal solution, no? Barring that, which is preferred? Antenna cut to theoretical reasonant length, and the impedance mismatch, or tuning (de-tuning?) the antenna to produce a better apparent match? I guess like you said, if it works for me, use it  I plan to build all my own antennas as my station grows. That's one of the few things that can still be easily and inexpensively homebrewed. I've been mentally trying to plan out some HF antennas for when I upgrade, based on what I can fit on my property (no antenna restrictions, thankfully). I also tend to go with simplicity and ease of installation... I'm thinking of tilted dipoles and/or inverted vees, high points to a roof-top mast. I definitely should do more research as you suggested. I'd found an excellent site on the internet about antennas, seemed to be THE antenna site, but I forgot to bookmark it and haven't found it again since

 - Mike, KD7TKQ

Hmmm... SWR meter might not be accurate, at least as an absolute value, as it was made for HF, but I'd assume that in any case the lower I can get the reflected reading the better, even if the meter wasn't designed for the frequency I'm using it on.

Wood had a thin but spotty coat of paint already on it (it was scrap), but I did not paint over it or over the wire. I put a dollop of silicone rubber sealant on the ends and the connections at the feedpoint for corrosion protection. The wire itself is insulated 16ga (speaker wire I zipped apart). As for after a shower, I suppose I could simulate one to see what happens, or wait until it rains sometime - a rare event where I am - Phoenix, Arizona. That's why I went ahead and used the wood, since I had it laying around anyway. If I lived in a rainier climate I probably would have gone with something else like small PVC pipe or some sort of plastic of fiberglass rod.

Just thought I'd throw in my own $.02 as another newbie. I was a bit hesitant myself. Not out of fear of speaking (anyone who knows be will tell you I can talk the, um, ears off a brass monkey). Not out of lack of confidence about using a radio (I've used two-way radios before in various jobs I've had, and was even into - dare I say it? - CB radio way back whenever it was actually a friendly place to chat). I was just afraid of making an idiot of myself, or not fitting in with the locals, or whatever. I'd already gotten a 2m HT as soon as I'd decided to get my ticket, so by the time I waited for the next exam session and then for my call sign to be issued I had almost a month of monitoring the local repeaters. Anyway, what I did for my very first QSO was I found a few people chatting on one of the repeaters, waited until they seemed to be done their QSO, then announced my call sign and that I was a new ham and would anyone like to be my first QSO. That afternoon I wound up spending a couple hours on the radio chatting with several different people. All were great, and either I didn't mess up, or (more likely) everyone was much too polite to call it to my attention.

So, just jump in and get your feet wet. It justs gets easier and more natural with each QSO.

I wanted a cheap and dirty 2m antenna for home. Didn't need to be fancy; just something to get me outside and away from the indoor QRM. Anyway, despite the fact that the J-pole seems to be the antenna of choice for VHF, I decided to go even simpler - a simple wire dipole, stapled to a length of 2x2 lumber for rigidity and to allow easy vertical mounting. I found a generic dipole calculator on the web somewhere which told me that (for 146MHz) each leg should be 19.26 inches. So, I made my dipole and stapled it to the wood and proceeded to check the SWR. About 1.5:1 - not good. So I proceeded to trim and check and trim and check... finally wound up with 16.5" legs (33 inches total). What I'm curious to know is why it wound up being so much shorter than the calculated size? Is it that dipoles behave differently at VHF frequencies, and the calculator was intended for HF? Or perhaps an effect of the wood it is stapled to? I suppose the important thing is that it works, but I'd still love to know why. Oh, and FWIW, I get under 1.2:1 SWR on 440, giving me the bonus of having a dual-band antenna.

Oh... if anyone is curious, the antenna is mounted on the roof by using hose clamps to attach the wooden antenna holder to a tripod-mounted 10-foot mast (I purposely left a couple extra feet of wood below the antenna itself for that purpose). The total height above ground is about 25-30 feet.