Greetings Ed!

 EV> 04-14-14 12:42 Roy Witt wrote to Ed Vance about Resurrected

 RW>> {at}MSGID: 
 RW>> 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.

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

 EV> I hadn't read that far into their restrictions.

 EV> But I'd try using the Mouse Wheel while holding the CTRL key down
 EV> to see if what they show of the Schematic could be enlarged so you
 EV> could use the Print Scr key to Save it as I wrote earlier.

It's displayed as a JPG and it is in a window so small, you can't do
anything with it. Besides, you would lose half of the schematic that isn't
displayed.

 EV>  Or Print it to a .PDF file. Hopefully the image wouldn't be so
 EV> Pixelated that it wouldn't be of use.

That won't work either.

 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
 EV>> then just remove the extra stuff to save the schematic as a .JPG .
 EV>> HTH -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 can't remember seeing any before the late 1960s.

 EV> I just remembered I bought a WineGuard TV antenna from my boss when
 EV> He Retired as Lockmaster at first Lock and Dam I worked at. That was
 EV> probably 1969 or 1970 but I didn't use it until sometime after 1974
 EV> when I moved to the city where I could get a TV Signal. That
 EV> WineGuard TV Antenna had VHF and UHF and now that I think about it,
 EV> I'd guess it is a Log Periodic Antenna, I never thought of it that
 EV> way when I first started commenting about LPA TV antenna to You, I
 EV> apologize for continuing this lenghty discussion about them.

The easy way to tell is by looking at it and determining if it has two
booms. If so, the likelyhood of it being a LPA is good.

 EV> When I lived in the country a hill blocked TV reception where I
 EV> lived. Although my neighbor who lived 1/2 mile closer to town could
 EV> get One VHF Channel, and we'd go there sometimes to watch TV. As I
 EV> told Bob Klahn, I listened to the first Moon landing on a Radio.
 EV> -snip-

I watched the 1969 moon landing on TV...

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

 EV> I Sure Did!

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

 RW>> 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.

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

 EV> If there was only One UHF TV Station that would be O.K., but it would
 EV> be hard to reposition the LPA if other stations were 90-270 Degrees
 EV> apart.

Hang them in different parts of you ceiling. I have an old six position
switch that requires BNC connectors, but RG59 is as easy to fix that
connector to as RG58...

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

 RW>> What were the dimensions of the CW antenna?

 EV> About 10 inches.
 EV> Radio Shack 2002 catalog on page 157 has a picture of one.

I don't have one of those catalogs.

 EV> They call it a Loop Replacement, number 15-233 and the cost then was
 EV> $1.99

Today it is called a Antennas Direct FM 360 antenna, sold at Walmart for
$36...although it is 21" in diameter and is for receiving FM radio.

 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
 EV>> looking to the older folks. -snip-

 RW>> Like rabbit ears...

 EV> Yes, rabbit ears for VHF, Loop (or Bow Tie)for UHF.

No reflector?

 EV> -snip-

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

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

 EV> I brought the Radio Amateurs Handbook upstairs and it says K = 0.95
 EV> IIRC. -snip-

 EV>>> I ran a wire around my radio room up near the ceiling, One Big
 EV>>> Loop. 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-

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

 EV> I would suppose everyone located near a transmitter site, Amateur,
 EV> Commercial or Citizens Band is exposed to RF aka a Faraday box?

Not if the radiating antenna is outside, above you.

 EV> -snip-

 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.

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

 EV> And IF I know of what book they can find the answer, I will tell them
 EV> which book to read.

If they're a smart ass and a pest, I don't mention which book.


    Have a day!

         R\%/itt - K5RXT

Being judged by McJerkey doesn't define who I am, it defines who he is.



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