True balanced line kW tuners for 160-10?

[K3ZS]

The "ladder-loc" works fine for window line.   It acts as a good strain point also.   You can get #14 window line.   Its Z is slightly lower but that doesn't matter for most applications.

[K5UJ]

what else have you guys tried for a ladder line center insulator? Seems harder to find than the SO239 version. Thanks!

 

I guess I don't understand the question.  It implies that some kind of special center insulator is needed for ladder line.

I just use a plain old dogbone porcelain insulator.   I have never used the plastic versions because when I'm soldering the ladderline to the dipole, I'm afraid the heat will melt the plastic.   I use a lot of silver bearing solder, get the wire pretty hot with a big 150 watt iron, and really saturate the connections with solder and they seem to hold up real well outside.

If I had it to do over again, I would use two dogbones tied together end to end or one of those big glass buzzardly dogbones that are around 6 inches long for the center insulator, just to get more space between the two halves of the dipole for when the center is at a voltage maximum.   No problems with one though, so two might be overkill. 

I saw one of the big glass dogbones at hamfest last winter but the guy selling it wanted a ridiculous price for it, around $40 as I recall, so I skipped it.   I think it was made with Pyrex.  If I were putting up a dipole made with no. 8 stranded and running shortwave broadcast level power, I would have bought it 

[K3ZS]

http://www.radiobooks.com/llock.htm

Look at this web site, the ladder lock is mainly used as a strain device for window line and also provides a tie point if you want to use a center support rope.   It is just convenient to use, you can solder the wires first before clamping it down.

[K5UJ]

Okay Thanks Bob, I think I have seen that before but it has been awhile and I forgot about it.

Rob

[KG4NEL]

Thanks for the advice so far. My situation changed a little bit - looks like I can run ladder line over the driveway, so a center-fed doublet all in the trees is what I'll be doing, with a Palstar balanced line tuner. If it works on 160, so be it, but not too worried about that.

Just one more question - how do you guys support ladder line going into the house, from a mechanical standpoint? I'm thinking some kind of a pulley system, but I could use photos of how other people have done it for inspiration Thanks!

[stevef]

The video just shows the spreaders, not the center insulator.

I tried his method but could not find suitable ink pens (black, and large enough inside diameter for a ziptie).  I tried some 1/4" black irrigation tubing but it will not allow two passes of a zip tie.   I then tried a piece of Pex 1/4" tubing which passes the zip tie, but unsure of its UV stability.

[Opcom]

Palstar's a very nice tuner for storebought, $$ too. You can build one that will work as well or better and the beauty of it is that of you run out of C or L, you can add more to a home made unit but not always easily to a storebought.

By your post, you may not have a center support. That makes it hard to hang the feed without a lot of tension on the legs to keep the center up, inviting breakage.

Is it possible to use any sort of support? The means of support does not have to be so serious as to keep the dipole from sagging, just enough to keep it out of the way.

How long a run from the center of the dipole to the building? There is nothing wrong with some slack, it will give you wind protection. If the feed is short, maybe the weight won't be an issue.

[k4kyv]

By your post, you may not have a center support. That makes it hard to hang the feed without a lot of tension on the legs to keep the center up, inviting breakage.

Is it possible to use any sort of support? The means of support does not have to be so serious as to keep the dipole from sagging, just enough to keep it out of the way.

How long a run from the center of the dipole to the building? There is nothing wrong with some slack, it will give you wind protection. If the feed is short, maybe the weight won't be an issue.

That should be less of a problem with open wire line than with co-ax, if the feeders are made from the same wire as the dipole legs (preferably using one continuous run, with no splice where the feedline attaches to the dipole), and  the spreaders, made of a lightweight material, are kept to the minimum number to maintain good spacing even under windy conditions. The biggest problem I ever had with an unsupported feed point was when my dipole was strung between two trees and it would get whipped around in the wind. Sometimes the 6" ceramic EF Johnson spreaders I was using would break in two, usually every other insulator. I have never had home-made spreaders fabricated from plexiglass rod to break under any circumstance.

At the mid-point of the dipole, use an ordinary antenna insulator, identical to the ones you use for end insulators (unless you use something like those nice 12" long ones EFJ used to make; in that case use a shorter insulator at the mid-point where the feed line is attached). Preferably, the insulator at the midpoint of a dipole should be the same length as the spreaders. If feed-point insulator is longer, use a heavy duty spreader for the first one at the top of the feed-line, so that the wire tension doesn't tend to pull it apart.

For a real classic look, use a set of three 6" Pyrex glass antenna insulators at the end- and mid-points.

[KG4NEL]

By your post, you may not have a center support. That makes it hard to hang the feed without a lot of tension on the legs to keep the center up, inviting breakage.

Is it possible to use any sort of support? The means of support does not have to be so serious as to keep the dipole from sagging, just enough to keep it out of the way.

How long a run from the center of the dipole to the building? There is nothing wrong with some slack, it will give you wind protection. If the feed is short, maybe the weight won't be an issue.

Nah, I'll have a center support - I'm planning on getting one of those WA1FFL insulators and tie off a rope to a tree, it just won't have a pulley on it like the ends.

[flintstone mop]

Try these folks for spreaders used in ladder line................if 600 ohms is your goal. I haven't had any failures for the last two severe winters. High winds,snow,ice

http://www.trueladderline.com/
They sold me the wire they use for their wire antennas.

Fred

[K3ZS]

My next antenna will be the one at the above website, that is a continuous wire from feedline and antenna.     I am presently using window line for feeders, but the tuning changes quite a bit on 40M and above when it is raining.    Almost impossible to tune on 10M when wet.

[WC1X]

I use a Technical Material Corporation tuner.  Model TAC-1.  Easily tunes down to 160.  Uses dual edge wound inductors. Vacuum cap for 160.  Very heavy duty.  Very heavy.  Very rare.  Works great.

[WA1GFZ]

WC1X I wonder if you could post some information on your TMC tuner?
How about a picture or two and a schematic. That must be a very well built unit.

[W0BTU]

Here's a copy of the manual I found in a Google search. Terrible quality, but better than nothing.

http://www.kevinchant.com/uploads/7/1/0/8/7108231/tmc_tac-1_antenna_tuning_unit.pdf

[W2XR]

WC1X I wonder if you could post some information on your TMC tuner?
How about a picture or two and a schematic. That must be a very well built unit.

Hi Frank,

Please see the attached link for the original technical manual for the TMC TAC:

Like nearly all things TMC, it is an extremely well built unit. It's design and production go back to the very early days of the company. I believe it was introduced around 1953 or thereabouts.

The top of the TMC GPT-750 Transmitter cabinet was pre-drilled at the factory for field installation and mounting of the TAC, or the more popular TMC ATS-2 Automatic Tuning System remote control unit.

73,

Bruce

http://www.virhistory.com/tmc/tmc_pages/tmc_manuals/manuals_db/tac/tm_tac_10-4-63.pdf

[WA1GFZ]

Very nice. I saw Teflon parts in the parts list so might be an updated manual.
I thought Teflon was a '60s thing.
I think John JN posted this tuner a while ago.

[W2PFY]

I guess the only thing I'm puzzled about is the use of 18 gauge wire used on some peoples antenna systems. That size looks as if it were intended for stealth or SSB operation. If your using it that's fine with me, I just think it's a bit undersized.

[W0BTU]

I thought Teflon was a '60s thing.

So did I. But PTFE was invented in 1938, and first marketed under the DuPont Teflon ® trademark in 1945 or 1946.

[KM1H]

In the early 60's it seemed to be everywhere in mil spec gear so Im guessing it was around well before that such as the Amphenol Teflon SO-239 in that tuner indicates.

[K5UJ]

I wonder how many of those TAC-1s were made.  Something tells me not many.

[WA1GFZ]

I think that tuner was the best 1 KW balanced tuner made.
I see TMC made many single ended tuners.

[W6KHZ]

I think that tuner was the best 1 KW balanced tuner made.
I see TMC made many single ended tuners.

My TAC-1 tuner is serial number 417.  I've used it in 36 hour RTTY contests running 1.2 kw and little or no heating was evident.  I guess you could probably run 4 kw SSB (1 KW AM) all day without issues.  To call it a 1KW tuner IMNSHO is a misnomer.

[K5UJ]

I think that tuner was the best 1 KW balanced tuner made.
I see TMC made many single ended tuners.

My TAC-1 tuner is serial number 417.  I've used it in 36 hour RTTY contests running 1.2 kw and little or no heating was evident.  I guess you could probably run 4 kw SSB (1 KW AM) all day without issues.  To call it a 1KW tuner IMNSHO is a misnomer.

Right--it was made in the heyday of TMC and AM and the "1 KW" probably referred to 1 KW input AM just like the KW Matchbox is by modern standards a ~ 2.5 KW tuner but the TAC-1 is probably still conservatively rated even by those standards.  Some of that may depend on the Z of the load at the TAC-1's balanced feed terminals.  IOW it might have been built to handle a lot of current at QRO.

[k4kyv]

I suppose it depends on your knowledge, experience and attitude as an amateur operator.  To me, the biggest Johnson Matchbox is a KW tuner.

Maybe "You think a Johnson Kilowatt Matchbox is a 2.4 KW Tuner" should be added to the following list:

You refer to one's name as the "first personal" or just "personal".

You end a QSO with "Seventy-Thirds" or "Threes".

You try to enter an ongoing QSO by yelling "Contact".

You finish an AM transmission in a QSO that is NOT operating fast break-in, and just drop the carrier with no prior warning like uttering a callsign or saying "over", "back to you", "go ahead", etc., leaving the other operator(s) wondering if you lost power or your rig crapped out.

You pronounce QRZ.com as "CUE ARE ZEE dot com".

You tell someone with a strapping signal he is "wall to wall, treetop tall".

You call operating AM "Going to the AM side".

You insert "there" between every two or three words in your conversation.

You call the phone bands the "SSB bands".

You think a "cold 807" is a type of tube (or you never heard of an 807).

You give everyone in a contest and every DX station you work a five-nine or 599 whether you can hear him or not.

You think the ideal horizontal antenna is the G5RV, and the ideal 160m vertical is 43 ft. tall.


What others can you think of?

[W6KHZ]

Here are some pics of my TMC TAC-1 tuner alongside my Johnson KW flashbox.
Notice the larger plate spacing of the TAC-1 air variable. 
I like both tuners but I'll never give up the TAC-1.