Thanks John!

I agree with you about the polarization being the main reason the antenna would work better at sporatic distances.

I may lower the antenna soon to replace the wire. (The oil/gas sheath is shedding off of the insulation. Not a big deal but it looks awful.) When I do this I may put it up 5' lower and see how that works for awhile since I'm using it for closer signals... you might be right that it could be better for that purpose.


BTW: My new website is now:

http://home.comcast.net/~keithlm/

As you probably know, ground mounted radials do not need to be measured or "tuned" as carefully. I think that to be "optimal" 80M radials would be about 66' in length.

I personally think the more radials the better. (And longer is better.) I believe that fifty 33' radials would still be better than ten 66' radials. (But then on the other hand... forty 33' radials AND ten 66' radials would be even BETTER.)

However, put them out any way you can. On mine, one side has shorter ground wires and on the other side they are longer. (On yet another side... I originally put in fairly short 20-30' radials... but I may dig up my gravel driveway and bury some longer radials.

I haven't really done much for the last few months. The bands are just so dead that I have no incentive at the moment. (Although I'd like to get a tower built before the bands open up.)

I am completely and totally sold on the MORE IS BETTER. It is my belief that we can all sit around and read about shortcuts and tests where people took shortcuts and make many wonderfulclaims. (For example the common claim that 4 elevated and tuned radials would be "almost" as good as a full set of 120 ground mounted radials.) BUT: I think that any compromise or shortcut is just that... a compromise or shortcut. Thus I say... put down whatever you can... as much as you can... take NO shortcuts.

Then LATER you can sit back and KNOW that you did not take any shortcuts and that you are not "compromised" in any way. I think the extra work is worth it just for that peace of mind. (And I know that I am willing to do a lot of extra work... just to have that little bit of "peace".)

BTW: I also bought the 1:1 balun that DX Engineering calls a "vertical feedline choke". (And charges about 3 times as much as it should really cost... but it IS good quality.) You feed the antenna coax and at the base the 1:1 balun splits it to the main feed and the radial system. I think it really did help a bit on decreasing the noise level. It also seemed to help on the transmit in various situations.

Good luck and just lay that wire out any way you can. But whatever you do... HAVE FUN. If laying out more wires makes you feel better.... THEN DO IT. If you think that you have reached a point where laying out more is not worth it... then you are good at at that point. Personally I don't think I will ever be at that point until I reach 120 radials all as long as the longest wavelength.

And even at 120... I might decide... "Hey 120 radials is the 'standard'. How would 250 radials work?" Again some would say... completely wasted effort. But then... have they tried? Do they know for SURE based on actual experimentation? Perhaps there is some point above 120 radials where something really neat happens that you can't model... but can only find out by actually putting down that many radials. I very much doubt that is the case... but hey... I like trying stuff. And even if NOT... you would still have put down ONE HECK of a good radial field.

Anyway... I ramble.

73 Keith -- AC0DV

It's spring so I am planning on a tower. (Or should I say still planning... or again planning?) I have ruled out a roof mounted tower. I don't mind house bracketed.. but I like the looks of the Universal aluminum self supporting towers.)

I have checked with local building and zoning. I can have up to 40' with no building permit. (I mentioned that if I bought a 40' tower... the antenna/mast/lightning rod might be a bit more than 40'.. they told me that was not a problem. Many locals have towers that are higher than that from years ago... so I figure the 40' is the current "conservative" height. Zoning at first said there was a 30' limit... but after checking further found that amateur radio towers are exempt from that rule and actually have NO height limitation. So I could get a higher tower if I want to get a building permit and go through the engineering plans etc etc etc.)

NOTE ON TERRAIN: I am on a "bluff". Within about 1 mile around me... the ground goes down about 200'-300'... so going higher is not as critical as if I was in the flatlands. Also being on a bluff I do get some strong winds... not usually bad... but that's why I'm looking at towers that are rated at almost double the "needed" load rating.

ANYWAY: I am considering two arrangements that would fit this height:

1. A 40' tower. (Model: 21-40 holds 21 sq ft load.) With this I could use a Force12 6BA which is their XR-5 with 2 elements for 40 Meters added OR I could get a Steppir 3 element probably with the 40M dipole.

OR:

2. A 30' tower. (Model: 35-40 holds 35 sq ft load.) To this I could get a Force12 4BA (10/12/15/17) and ALSO a 420/240. The 4BA has more elements (and gain) than the 6BA. The 420/240 stands for 4 elements on 20M and 2 on 40M. I would put the 4BA at the 30' level and the 420/240 at the 40' level. (Most likely using a 16' mast from Universal.) THIS arrangement would require either 4 runs of coax OR a remote switch. (Probably the remote switch for now.)

I think that "in theory" the Force12 4BA and 420/240 combo stack would be the best option. However, I have never had a tower or a beam... so perhaps I might not be taking something into consideration??

I do figure a stack will be fairly high maintenance and I will probably have to climb up a lot more. Also... with the stack option I can hold off buying the 4BA for now because 10/12/15/17 are fairly dead right now.

A consideration is that the 40' tower would make a good place to setup an inverted  V or perhaps play around with slopers. The 30' could also serve this function... but not as well. So that's a point for the taller tower.

NOTE: I have a HyGain HyTower(JR) vertical for 80-10 on the other side of the yard... about 100 feet from where I would put this tower. (Currently with 80 radials.) I may someday change this to a regular HyTower.

Anyway... anybody have input or opinions? Should I keep considering the more elaborate stack or ditch that idea and go for something easier. (I like the challenge either way.)

tx 73
AC0DV
Keith

I also say IC-718.

However, I add a caveat:

Plan on replacing the murata ceramic filter sometime down the road.

This way you can get the radio NOW for less money... and then by adding better mechanical filter(s)... you get better receive and transmit audio on SSB and possibly a nice narrow filter for CW.

I recommend the "one board filter". It replaces the existing Murata SSB filter AND also adds a new CW filter. If you absolutely will never do CW... you can do just the SSB filter.

This is one of those upgrades that many people have different opinions about.

I say YES! I couldn't go back to NOT having it. It's required for CW and once you use it on SSB you won't want to go back to not having it. It really does make the incoming audio better. (In my opinion.)

I was looking through various literature and came across a 9' fiberglass mast (2" diameter) sold by GlenMartin.

Does anybody have any experiences with using fiberglass masts instead of steel or aluminum?

Are there any benefits over steel?
(Other than being lighter.)

When modelling a yagi... the yagi appears as a dipole with director(s) and/or reflector(s) in free space. I don't think the boom is part of the model... neither is the mast or tower.

Could isolating the boom from the tower actually have any effect on the yagi?? Perhaps it would actually make the antenna "appear" to be actually higher above ground?

I am working on getting up a tower. Then one of my next tasks after that project will be playing with more horizontal antennas.

For a wire antenna I am currently using an 80M full wave horizontal loop "skywire". GREAT RX antenna if you have the room. OK on transmit... not as good as my ground mounted vertical with 80 radials.

I also have an Alpha Delta DX-LB which is a trapped 160M/80M/40M dipole. I had this up for awhile.. but it never worked as well as I would have liked... it was mounted East/West as a "flat-top" so it was way too directional.

With a new tower I can play with new configurations of wires:

1. Inverted V. The DX-LB might work much better.

OR:::

2. I can remove 1 side of the DX-LB and use half of the antenna as a "SLOPER" similar to the DX-B. I could also use the traps and make a two-sided similar to the DX-A but that would take a lot more work.

NOTE: I've read that slopers can be WONDERFUL... or they can be AWFUL. It seems it's not predictable... it's very location dependent.

AS SUCH: If you plan on buying an Alpha Delta... you could consider getting one of the "full" dipoles like the DX-LB and just removing one side to try it as a sloper. Then if it doesn't work well... you still have the "other half" of the antenna... and can make it into an inverted V.

This would all depend on if you consider the extra money worth it for "insurance". I would... because I like changing my horizontal antennas a lot.. just for fun. So I'd want it just to see how a "normal" dipole using the same traps would work.

Oh sorry... "Iso-Res RF choke coils" I didn't mean to call them traps... :-)

Good Luck, 73
KEITH AC0DV

Every time I try to take a shortcut or save some money... people jump in and talk me out of it. Darn them.

Just because they bring in salient points that are correct and logical...

Okay. I'll get a 40' Rohn 45.

I'll use a 5' short piece dropped down in cement. (An amount of cement somewhere between what they suggest for self-supporting and the amount suggested for bracket mounting. Just to be safer.)

In addition, I'll build a Gin Pole and "have done" with the idea of any kind of tilting-over. Tilting over would mean something was very awry.

This will give me a VERY strong 40' tower that probably would be fine self-supported... but will also have a bracket mount at about 20' or so and maybe another one lower down.

The rohn catalog says a 40' rohn 45 bracketed at 30' can handle 27 square feet of wind load.

A "self-supporting" rohn 45 of 20' will support 16 square feet of load with a 1/2 inch of ice.

The top 20' of a 40' bracketed at 20' would be similar to a self-supported 20' section... although definately not as strong. BUT... using the rohn literature... I can extrapolate that a 40' rohn 45 with a 20' bracket and no guys should handle at least 10-12 square feet. And with guys... even more.

Anyway... thanks again for all the input. I've changed my mind several times... but I can agree that shortcuts are bad. Even if others have taken these shortcuts and survived.

(And I'll look into something made of rubber to cushion the house from the bracket mount.)

--Keith

Thanks for all the opinions.

Based on the feedback I think I'll go for a 40' tall Rohn 25 ground mounted and bracketed to the house... I will also add some guy wires at the 38' level just for added strength. The literature at Rohn suggests that a bracketed tower with the bracket at about 20' should be good for 30'-35'. (And I'm sure it would be fine for 40' since they "over-rate" things. But I'll guy it just for the added safety anyway.)

I think I'll also get the 3'4" hinged section and bury it in some cement.

Apparently Rohn says not to tilt the tower with any equipment attached. Apparently many people do it all the time. (It doesn't make sense to make a tilt-over that can't support anything but itself... but I digress...)

I think I can use the winch on the front of my Jeep and a snatch block mounted to a large bolt as high on the house as I can go. (The winch is rated at 8000 lbs so it should work as long as I make a REALLY good attachment point for the snatch block on the house. BTW: "Snatch Block" == A Big Pully meant for vehicles.)

As for the NOISE issue... I'll use the longest/largest bracket that Rohn makes... it allows it to be 36" away from the house. But luckily the place I would attach is on the opposite side of the house from the bedrooms.

So... that's my current plans. I'll keep researching the tilt-over and decide later.

Total price to buy LOCALLY with no shipping charges: $1101.00 with tilt-over base. $839 without. $1402.00 for a Rohn 45 of the same height. (So $300.00 more for the 45?? That's a definate possibility.)

Anyway thanks again!
--Keith--AC0DV

Thank you for the replies. I can see advantages to both types of towers.

BTW: The gentleman at zoning said that variances start at about $500.00.

HOWEVER: I DO think the zoning guy might have been incorrect. Reading the zoning rules PDF on the net... it clearly says that private towers are excluded from the "maximum height rule" and that for my "zone" the height for a private tower is 2 times the height limit for detached and 1.5 time the height limit for attached private towers. Using his 35' height limit as the maximum this gives us 70' and 52.50'. (The online height limit appears to be 30' but there is a place where it proposes a change to 35'. Worst case... that makes it 60' and 45'.)

These 70' and 52.50' limits include the "main structure and any retractable, non-retractable extension, or antenna".

The BUILDING permit person specifically said no building permit needed if it's less than 40' and did not include a "platform".

So I'm thinking a 35' tower... and a 10' mast for now. If there is an issue... I remove the 10' mast and use a short mast. I reach the figure of 35' by using 3x10' and 1x9' (top) sections with the bottom section 4' in concrete.

I agree with the "benefit" of having more expandability in the future if I use the Rohn sections.

Plus... I suspect a cemented and bracketed Rohn 45G is probably stronger at 35' than a 17.5' roof tower would be. (And perhaps less scary to climb?)

Thanks again... My brain is trying to take it all in.

Keith

No more guessing and wondering. I checked with my county and they will allow me a 35' tower without any kind of license or paperwork. (Although I might get some paperwork from them that says I don't need any paperwork just to be "safe".)

Now I have to decide on a tower for a tribander:

CHOICES:

1. A roof mounted Glen Martin tower at 9' or 17.5'. The roof is about 17' or 18' tall. (So total of either 27' or 35'.)

OR

2. Ground mounted Rohn 25G or 45G bracket mounted to the house at about 17'. This tower would be made of 2x10' sections, 1x9' top section and a 1x5' ground section mostly buried in cement. (So 30' tall.) Or perhaps I could use 3x10 regular sections and 1x9' top section. The bottom section would be buried 4' into concrete. This would put the top at about... 35'.

===================

I think I could use a tilt-over method to raise the antenna on either of the Glen Martin roof towers. The Rohn I'd have to climb.

NOTE: The antennas I'm considering are the Force-12 Delta-6BA or C4XL which are 11.5 sq ft or 8.2 sq ft. I also looked at a Steppir 3 element with the 40M dipole which has 8.1 sq ft of load. All the weights are within bounds.

RATINGS:
The GM roof towers are rated at 18 and 12 sq ft. (For the 9' and 17.5')

I think the ROHN tower would be somewhere around 11.5 and 25 sq ft for the 25G and 45G. (I'm getting these ratings from looking at what Rohn has listed for bracketed installations and also what a 20' self-supported installation can handle and averaging.)

PRICES:
The GM would be: $440.00 for 9' and $585.00 for 17.5'.

The ROHN would be "about" $650.00 for the 25G and $1050.00 for the 45G. (This includes 2 house brackets for the Rohn. This is assuming I can get the Rohn locally without paying huge shipping costs. If I can't... then forget it... because it would be between $250.00 and $400.00 just for shipping. The GLEN MARTIN can be sent UPS.)

=========================

Does anyone have thoughts on this issue?

My plans are leaning towards the Glen Martin roof-top at this point because of price, shipping, and also it is harder to climb since it's on the roof. Then I can decide on the antenna. (Using a Hy-Gain TX2 Tailtwister to rotate them.)

Thanks and 73,
AC0DV

Some pictures of my loop installation at:

http://users.adelphia.net/~keithlm/586/

Oh... and I forgot to mention in my long post.

On 3 of the corners run the wire "loose" through the insulator so it can move easily

On the fourth have the insulator attached to a pulley/weight of some type. That way when the wind blows... and the trees sway... the loop will NOT pull tight and break the wire.

Last weekend I installed a 80M full wave loop skywire.

I used 3x30' antenna masts and 20' of PVC.

NOTE: Loops take much less tension than a dipole to hold it up in the air. Using antenna masts is overkill for this application... but I don't mind overbuilding.

The fourth corner I used 20' of PVC. It's about 10' higher than the other masts due to a hill... so the entire loop is level.

Anyway... my diatribe is getting to a point... I think you'll be just fine using the cable you plan on using. There may be some coupling... but the nature of the horizontal loop will probably make that minimal anyway.

By "nature" I mean that the horizontal loop is generally used with a tuner and they are not usually cut to resonance.

You CAN cut it to resonance if you really don't want to use a tuner... but it doesn't make it work any better... and doing that defeats one of the largest advantages of the loop... multi-band use.

Because the loop is used with a tuner and the length is not critical... some coupling should NOT affect things very much.(Unless you couple to something BIG or LONG.)

So... most of the time you get the same advice for loops: Longer and higher.

==================

PERFORMANCE: Wow. I forgot how nice it is to have a really GREAT receive antenna with low noise.

For the last couple of days I've been hearing and working contacts that I couldn't hear before on my vertical or my older 160/80 trap dipole. (They receive too much noise.)

I'm in HEAVEN. It is night and day. The loop even transmits well.

(Although 70% of the time my vertical transmits better. I might get a good switch that will transmit on the vertical and receive on the loop. I switch to the loop for receive then forget to switch back when I transmit.)

Anyway... get the loop up and ENJOY IT!

73
Keith
AC0DV

Every time something really cool happens in one direction... I get other results in another direction.

On 20M today... both the vertical and my new loop transmitted with the signal being received at about the same on the other end.

Of course receive on MY end had a MAJOR advantage.

NOTE: Without the loop... I could not have worked the contacts. (I could hear them good on the horizontal loop... but barely if at all onthe vertical.)

Made me feel like I've had ear-muffs on for a year.

ANYWAY: I've concluded that you need both a good vertical and a good receive antenna.

(That's for omnidirectional purposes. A tower and a good directional is STILL in my future plans.)

JOHN: I think you'll be pleased with a vertical delta either fed with a matching stub and coax... or all the way in with open line.

(And if you can get a link coupled tuner to use with the open feed line.. you'll appreciate the efficiency.)

I am getting some RFI on my loop's transmit... using my Matchbox. This tells me I need to work on a better method to get the ladder line into the shack. (Right now I just slip it into the sliding window... which is plastic... so it shouldn't matter too much.

Anyway... good luck with the delta loop.

73
Keith
AC0DV

I just went with a single 278' wire loop at 35'.

It receives signals so much better than any other antenna I've ever used.

Most of the time my vertical with the 80 radials transmits MUCH better. This is even true for "closer" contacts... contrary to the NVIS principles but true nevertheless.

(I'm talking about a 3-5 "S" units of difference on the receiving end... so a like a 12db difference??)

I like having the loop... it is VERY nice having a better receive that has much less noise than my vertical.

Now I just have to get a T/R switch to switch between them... I keep switching by hand and then forgetting to switch back on transmit... so they often can't hear me.

73
Keith
AC0DV