Re AA4PB's question, there is a difference between strands insulated and touching.  Litz wire has strands individually insulated.  Ordinary stranded copper antenna wire is of course not insulated strand-to-strand.  Thus the flow of RF on the surface is actually a hill-and-dale, with a spiral direction.  Visualize water seeping along the wire, taking longer to go a distance vs a nice, smooth pipe.  

But again to the practical, makes no difference in HF wire antennas.

John

First the theory:  Propagation on a stranded wire is slower than solid because the RF (which flows on the surface of each strand)actually has to travel farther than on a smooth (solid) wire.  This effect can be best seen with high grade coax with stranded center conductor vs that with solid.  All of the super-low loss coax uses solid for that reason.

Now for the practical:  For a wire antenna, it makes no difference.  Use whichever you have, or prefer.  Continuing with the practical, stranded hard-drawn copper (14ga) is my preference since it is much easier to work with compared with copperweld (very springy, don't let that spool get away from you!).  Radio Works and other places sell a nice 7-strand 14ga hard drawn wire at reasonable cost (about $.09 or $.10 per foot).  For 12ga wire (longer antenna spans), I haven't found an equivalent, but have used the Flex-Weave (many, many strands, very flexible, almost like small rope, you can even tie a knot in it).  There is also a 14ga version.  However Flex Weave is more expensive and thus not my first choice.

House electrical wire (stranded THHN) sold by Home Depot, etc is quite cheap.  However it is insulated (and thus the resonant frequency will be a little different from bare of same length).  Also the insulation makes it heavier (more droop, sag), and as pointed out above, is soft copper, and will over time stretch (wind and ice will accelerate this process).  So THHN is best used for shorter antenna legs and places where you might want some insulation (tossing a wire directly over a tree limb, for example).

John.

I think most of the older tuners are good choices.  It seems you get much heavier parts compared with the lower and mid-priced tuners of today.  My own is a Dentron RT-3000.  Their MT series is also very good, and available frequently on eBay.  Also check out the Daiwa tuners (vintage early 1980's).  Well built.  The MJF's scare me.  I've heard too many stories about not handling the rated power.

Also remember that the older tuners, if rated for AM, are really rated for much more PEP.  For example a 200 Watt AM tuner would today likely be rated 800 watts PEP.  

Like an above post, I prefer the manual tuners.  Higher efficiency. Some of the auto tuners really have some small inductors, so if you notice the ads don't highlight their losses.  I hate to give up 10 or 20% of my power.

Either way you should be fine.  I have a 30L1 and one of my 811A's burned up.  Another one was running hot.  So I decided rather than buy a new set of 811's, to get the 572B's.  Plugged right in, no problems.  No adjustments.  Output power with the 811a's (before tube failure) was 800 pep.  Now 800 to 900 pep.  THis is with about 1700 volts or so on the plate, under full load.  So if your voltage is on the lower side, you won't get more power, but the tubes will run black (vs showing some color on the 811's).

Of course with higher voltage you can run more power with the 572b's since plate dissipation is about 160 watts ea vs 65 watts.

I strongly recomment the Chinese 572's rather than the Russian.  Chinese are sold by some as "Taylor" brand, about $200 per quad matched.  I bought the same tubes (without the Taylor branding) from Penta Labs for $140 matched.  The Russian tubes are somewhat different, and some have had some problems in some amps.

On the other hand, the 811's are fine tubes and will give you many years of service if plate voltage is in the range of 1500 to 1800 volts.  And cheaper than 572's.

John

You are asking some rather substantial questions that deserve some good answers, but more so than what you will likely get in these posts.  For example a 134 ft wire is a resonant 1/2 wave antenna on 80 meters, and will have a feedpoint impedance in the area of 50 to 70 ohms.  On 40 it will be a very high impedance.

Might I suggest that you go to http://www.arrl.org/tis/tismenu.html (the ARRL web site, tech info area).  There are several good articles about antennas.

Another excellent source of info is http://ac6v.com/antprojects.htm

Good luck, and welcome to ham radio.  John

I purchased a KWM2A about 2 yrs ago. Just love it.  I'm getting very high quality audio reports.  Very well designed.

Like all vintage equipment, you would need to be prepared (or have someone else) replace weak tubes, probably all of the electrolytics (precautionary), and do a general tune-up.  Might work without doing anything, but worth the effort.

The "A" has extra crystal switch positions, so you can install crystals for 10mhz, 18mhz, 24mhz.  Thus it's somewhat preferred vs the non-A.  It seems most Collins equipment has doubled in price over the last 5 yrs or so, so pretty good investment.

I use my Collins equipment exclusively (don't have new stuff).  Have worked 180 countries in 21 months.  I think it (and other good vintage equipment) is like driving a classic (vintage) car - it doesn't do everything a new one does, but you don't expect it to, either.

DPDT coaxial relays are available on ebay from time to time.  Currently there are two,

5755427868  (from England, $86 plus shipping)
 
3015171688  This one is via henry radio, which carries a wide line of relays.

I have seen other DPDT DowKey, etc on ebay at fairly reasonable prices.

John.

I currently switch between four legs of a long-wire V antenna, so essentially same situation as what you are asking.  My relays are from Grainger, 30 amp contacts.  Plenty beefy for max legal power.  

You might try their 3X749 (DPDT 24VDC) or 5ZH61 (a little cheaper).  For lower power almost any smaller relay with 10amp contacts would work.

24VDC coils are better than 12vDC since less current, therefore less drop in cable to relays.  Obviously don't use 115v relays since that is dangerous.

Home Depot sells a little 4x4x4 waterproof Carlon brand plastic box in the electrical dept that will hold the relay.  In my situation the antenna legs connect to the relay with some bolts sticking out of the top of the box.

If you subscribe to QST, the May issue is tentatively scheduled to have my antenna article, which shows a picture of my relays.

John

Go to http://www.arrl.org/tis/info/pdf/9501046.pdf for good info on adjusting a tuner for good SWR and low loss.    John

Check out http://www.arrl.org/tis/info/pdf/9501046.pdf   This is from the ARRL tech support site.   Good general info on how to adjust a tuner for good SWR and low loss.

John

Evening grey zone will be almost north-south by date of your trip.  Thus from Tocopilla, you will be somewhat early for California (almost perfect for midwest).  So grey zone might not help you that much.  However with the sun nearly over the equator, general propogation between Tocopilla and US should be better than either winter or summer.  Like above post, I think you will do fine.    Northern Chile is a very interesting area.  Enjoy.   John.

I just noticed that www.radioworks.com has a UHF to RCA adapter for $1.39.  Their number #904.    John

I made up a short patch cable using RG8X (RG58 would also be fine), with a PL259 on one end, and a Radio Shack metal RCA male plug on other end.  Works fine.

Welcome to a great hobby.

There are so many aspects to ham radio, and at least in the beginning, so many questions, that I recommend that you contact a radio club near you (assuming there is one).  Attend a meeting, indicate that you are just beginning, and I'm sure you will find other hams willing to help you get started.  Cheaper than making beginner mistakes, and more fun.  

Also field day will be coming last weekend in June, and that's a great opportunity (with a club) to meet others and operate some equipment.  Even if you only have a technician license at that point, you will, under the guidance of another ham, be able to make HF contacts.

You can check out clubs in your area by going to www.arrl.org, click on the "clubs" button at the top left, and enter your zip code.

Good luck, John.  

Sorry I can't give you any advice on the calibration problem.  But you certainly should get better than you have - my 1948 Millen model is perfect, and has never had to be opened.  Still use all the time.

You didn't mention if the calibration is off the same amount (physical distance) on the drum with all coils.

John