Greetings Ed!

 RW>> Well, there are 3 schematics for that radio on that site. I'd
 RW>> like to have a copy of them, but the radio has a schematic
 RW>> attached to the inside of the back cover and it's readable,
 RW>> with a magnifying glass.

 EV> I haven't been back to that site, but anything I see that I want to
 EV> keep a copy of I use DoPDF to 'print' a .PDF of it.

The problem with that is that you have to become a member before you can
get a large enough view of the entire schematic. They display them in
partial views only and those aren't big enough to read.

 EV> If they show a schematic try DoPDF or even use the Print Scr key and
 EV> use some program like Irfanview to Paste the Clipboard into, and then
 EV> just remove the extra stuff to save the schematic as a .JPG .
 EV> HTH
 EV> -snip-

 EV>> I don't think I even had heard of a Log Periodic Antenna in the
 EV>> early to mid 1960's.

 RW>> Ummmm. They were on every rooftop of houses with a TV set. Most
 RW>> of them were dual banders, aka VHF and UHF...when I worked for
 RW>> Solar Turbines in San Diego c1967, a younger friend and I built
 RW>> a few for our own use. He was a tool & die apprentice, I was
 RW>> t&d journeyman at the time and he lived two blocks down the
 RW>> street from me.

 EV> I only remember seeing Yagi TV antennas on houses, mostly VHF only,

1940s & 50s...

 EV> though sometime later I seen a UHF over a VHF antenna.

When UHF began, you saw UHF antennas on the same mast as a VHF Yagi.

Later, they made VHF/UHF antennas all in one.

The LPAs came along in the late 60s.

 EV>> And it would be a bear to make and position by the TV Set.

 RW>> There's a video on YouTube showing how to make one out of
 RW>> stripped RG59 coax (using the shield only) as the electrical
 RW>> 'boom' and #12 house wire as the radials. It is only 58cm
 RW>> (22.6") long. The support boom is made out of wood, 1" square,
 RW>> and all radials are wood screwed to the coax boom at a
 RW>> specified spacing.  Crude, but affective. The video shows the
 RW>> builder holding the antenna pointing it out of the window,
 RW>> waving it about, the TV HD signal fades and brightens as he
 RW>> finds the station's xmitter site.

 EV> Thanks!, but that rig would be cumbersome to use IN a bedroom.

It's less than 20" long and you could always have it floating near the
ceiling, once you found the direction of the station you want.

 EV> My Twin-Lead Folded Dipole was replaced by a Circular Wire antenna
 EV> after other UHF TV Stations came on the air.

What were the dimensions of the CW antenna?

 EV> The antenna I made just drooped behind the TV Set, the newer one
 EV> could be turned to adjust for the best picture, and was nicer looking
 EV> to the older folks. -snip-

Like rabbit ears...

 EV>> Tonight I looked at a ruler and that seems about the length that I
 EV>> recall the antenna being.

q

 EV>> My 19 CM guess earlier was way off the mark, wasn't it? .... ..

 RW>> Yes, it should have been about 19 1/4 inches.

 EV> Half of that for the 'half-wave' folded dipole I made.

Closer to 10" ...

 EV>> I do the best I can with what I got, but when I really want to know
 EV>> something I go to the Books I have to get it down to the nitty
 EV>> gritty.

 RW>> I keep a formula in my head that allows me to figure a 1/4 wave
 RW>> antenna. Multiplying that by 4 and you get the full wave
 RW>> length.

 EV> See above.

 RW>> 2808/freq in MHz * 4 = a full wavelength.

 RW>> 2808/582 = 4.825 x 4 = 19.24"

 RW>> Somebody asked me some years ago in the HAM echo where I got
 RW>> that 2808 number. Which had something to do with figuring the
 RW>> length of a dipole and a number around 5600. It's been so long
 RW>> since I figured that, I have forgotten what it was.  Anyway,
 RW>> building 1/4 wave GPs that 2808 number worked out very well, as
 RW>> each one of those antennas made for 450 MHz, had less than
 RW>> 1.2:1 VSWR across the entire 10MHz of that band. As would be
 RW>> expected, the 145Mhz and 220Mhz antennas worked just as well.

 EV> The only Antenna Formula I think I can remember was either 468 or 486
 EV> over the Wavelength (or Frequency) = Frequency (or Wavelength).
 EV> Haven't made any antennas for years and I'd have to go look at the
 EV> book first before I'd cut any 14 AWG Copper Wire.

That probably equates to feet and inches. The one I always remember is
300/Frequency in MHz = wavelength. But that gives you a metric answer.

Yeup, 300/28 = 10.7mtrs...468/28 = 16.7 feet.

 EV> (Later) I just wasted a lot of time looking around on Wikipedia for
 EV> the correct number, I looked at Antenna, 486, 468 and did some other
 EV> searches there and gave up.

I recall the dimensions easier than that number. If I plug 486 into the
formula, 486/28 = 17.35 feet. Getting closer...

 EV> None of the books I have in the room where this computer is were able
 EV> to help me either.

The ARRL Antenna Handbook (CR-1974) says it best: 'A length/diameter ratio
of 10,000 is roughly average for wire antennas.' Known as a factor K in
figuring the length of a wire antenna. Length in inches = 5905 x
K/frequency in MHz...and they show a chart of the difference along a wire
in space and the real thing.

 EV> I 'thought' the "The Great International Math On Keys
Book" that was
 EV> included with the Texas Instruments TI-30 Calculator I got in the
 EV> 1970's would have it for me, or another Scientific Calculator I have
 EV> that had a book with it, but NO, nothing I looked at showed me what I
 EV> was trying to find.

If you take the above and you want to make a 1/2 wave dipole, you use half
of the number 5905. Each leg will be a 1/2 wave. i.e. 2952.5/28Mhz = 105.4
inches, which is nearer to the length of whips sold for 10mtrs...your car
or vehicle is the other half of the dipole.

 EV> So I went and got a Handbook to see the number is 468, but my idea of
 EV> the Formula it was used in was all wrong.

 EV> Length of Half-Wave Antenna (feet) = 468 Divided By Frequency in
 EV> Megacycles.

= Feet...

 EV> DUH!!!!!!
 EV> -snip-

 EV>> I ran a wire around my radio room up near the ceiling, One Big Loop.
 EV>> I used  it with the DX-40 on 20 Meters.

 RW>> Not for transmitting I hope.

 EV> SURE!, what else do you use a Heath DX-40 for?
 EV> -snip-

So, you lived a dangerous life in a RF environmet, aka a Faraday box...

 RW>> Not only that, but the radio was xtal controlled xmit only. It
 RW>> had a tunable receiver. That was nice for listening to off
 RW>> frequency radios. My Golden Eagle had that too, but it could
 RW>> switch to a set of 23ch mixer controlled receiver too.

 EV> My DX-40 was Crystal Controlled (Only) until I got my General Ticket
 EV> and used a Knight-Kit VFO with it.

Yes, as I recall, those days a Novice was required to use xtal controlled
frequency radios.

 EV> CB Radios HAD to be Crystal Controlled until (I think) until the
 EV> Phase Lock Loop circuit was used in them.

Phase locked loop and later the digital frequency oscillator...

 EV> I don't know nuttin about PLL, but I'd think they have One or Two
 EV> Crystals in the circuit???

Yeup. Even then, all a CBer had to do was change one of the mixer xtals
with another and come up with 4 unauthorized channels. Or do as I did to
get a clean operation from my car to the house, swap xtals around so that
you listened on one channel, but xmitted on another. My CB base station
was always heard loud and clear where I worked in downtown San Diego and
the morning rush hour was plagued with too many conversations to make
conversing with my wife in Clairmont difficult at times.

 EV> There's lots of other things I never figured out how they work, such
 EV> as J-K Flip Flops........ SO I guess I'll never become Mr.
 EV> Know-it-ALL.    .... ..

I experimented with that stuff many years ago, but lost interest.

 EV> A Friend who went to Navy Electronic Technicians School, told me his
 EV> instructor said not to try to remember all the formulas, just KNOW
 EV> where the book is that has them in it.

Now that's the best advice one can get. My other favorite was to reply to
the 'I want to learn' this or that questions was: go read the book.

    Have a day!

         R\%/itt - K5RXT


--- GoldED+/W32 1.1.5-31012
--- D'Bridge 3.99