M104C Project

[TimmyTheTorch]

Test lift with the rotor and 12" aluminum mast in place went well. I still need to align the lower rotor mount and upper thrust bearing mounts. Looks like it's time to start assembling the M104C. And I just realized I have not yet ordered the coax I need for the second antenna and also the jumper cables for the Palomar Maxi-Choker for each antenna. And I need to decide where to put the other two guy wire anchors on the roof (the third wire goes to the post I installed a few months ago). I need to do additional research to refresh my brain on how best to do this to have it a) strong and b) waterproof. Right now I have the guy wire ring on the mast halfway up the top section. I may move it higher depending on how it all shakes out.

My wife is very glad the base mount stuff is all on side of the house not visible from the road. I'm a bit doubtful she knows what the M104C actually looks like. I think they are beautiful but, well, we'll see. When I was a kid I dreamed of having a Super Laser 500 (8 horizontal, 8 vertical) so the M104C is just a pipsqueak!

 

[TimmyTheTorch]

Hmmm, I have two of the Palomar Engineer Maxi-Chokes, one for the M104C and one for the V58. The beam is being mounted horizontally and it looks like the best plan is to mount the Maxi-choke as close as possible to the antenna feed. I plan on sticking with RG213 coax like I use now for the V58. The Palomar site shows the choke mounted on a horizontal yagi and it looks like a right angle adapter is used instead of using a patch cable with a right angle PL259 end soldered on (if such a thing exists). I have some really good waterproof tape I will be using for all of these connections so hopefully using a right angle adapter doesn't cause me any new issues. I am starting to be able to see the finish line and I don't want to get sloppy in my growing anticipation of being back on the air.

 

[Shadetree Mechanic]

Hmmm, I have two of the Palomar Engineer Maxi-Chokes, one for the M104C and one for the V58. The beam is being mounted horizontally and it looks like the best plan is to mount the Maxi-choke as close as possible to the antenna feed. I plan on sticking with RG213 coax like I use now for the V58. The Palomar site shows the choke mounted on a horizontal yagi and it looks like a right angle adapter is used instead of using a patch cable with a right angle PL259 end soldered on (if such a thing exists). I have some really good waterproof tape I will be using for all of these connections so hopefully using a right angle adapter doesn't cause me any new issues. I am starting to be able to see the finish line and I don't want to get sloppy in my growing anticipation of being back on the air.

View attachment 64466

I would leave the 90 degree connector off and just go straight into it. Doesn't seem like it needs a drip loop either.

 

[TimmyTheTorch]

I would leave the 90 degree connector off and just go straight into it. Doesn't seem like it needs a drip loop either.

Based on the distance between the mast and the antenna feed, I think a 1 foot RG213 patch cable should work. I will find out. The additional coax has now been ordered from a bloke I've had great results with in the past. Coax I was receiving from Amazon vendors was too hit-and-miss for my liking.

I also need a surge protector for the beam and was going to get an Alpha Delta ATT3G50UHP based on some Dave Casler videos I watched. This model seems to be out of stock a lot of places and quite pricey at other places that do have them in stock. But I'm not going on the air with the new setup until I have all of the right bits in place. Good thing I am off the rest of the week so I have lots of time to mess about.

 

[Marconi]

Tim, you're having lots of fun with your new project. I wish I could still do the same.

Best of luck and God Bless you,

Marconi

 

[TimmyTheTorch]

Tim, you're having lots of fun with your new project. I wish I could still do the same.

Best of luck and God Bless you,

Marconi

Thanks Marconi. I am trying to put to good use all of the things I have been learning here.

Back around 1980 when I was a kid, my best friend and I got plans from something like CB Magazine for a home made PDL2 and decided to give it a go. We could not afford aluminum tubing so we spent hours wandering through my friend's 100 acres of woodland looking for just the right trees or branches for the 18 foot long elements and finally found four each. We bought some coax and wire and a few little squares of plastic on which to mount the feedpoint. We then got them up about 20 feet in the air, tuned them a bit and much to our amazement they actually worked! Not bad for maybe $15 each. My life now sure would be simpler if my brain would let me do the old-style builds again.

 

[TimmyTheTorch]

I was able to order the Alpha Delta ATT3G50UHP from the same place I bought the M104C. They have it in stock and I've had good luck ordering from them in the past.

 

[linearone]

I was able to order the Alpha Delta ATT3G50UHP from the same place I bought the M104C. They have it in stock and I've had good luck ordering from them in the past.

I would have done a tuned stub at the base for lightning protection.

 

[G-Golly Wally]

Looks good! I'm sure you'll enjoy DX even more with the satisfaction of setting up this project your self. I like to see what others come up with that way I can steal ( I mean barrow) some ideas.
Good job brother, enjoy!

 

[TimmyTheTorch]

I assembled the elements, boom and gamma match for the M104C the other night and my wife even helped me do it. The extra set of hands sure did make measuring the element lengths a lot easier to do. Today I mounted the boom on the mast and gave it a test lift to make sure it was going to clear the Dish TV dish at the back corner of the house and it does. I sure do like being able to raise/lower this stuff by myself just using a cordless drill.



I also soldered the connector for the Yaesu rotor and will be testing the control box after dinner tonight. I have a temporary 10 foot mast setup in the backyard to use when mounting the elements to the boom, putting the V58 above it and tuning it. I can't get back at this until Thursday and it is supposed to rain tomorrow so I will leave that until Thursday.

The rest of the coax I need arrived yesterday so that's been added to the pile.

I was able to learn how and where to mount the guy wire anchors on the roof without causing a bunch of leaks. A friend showed me a gizmo called a Chiptoolz Rafter Center-line Locator. I watched a few videos on it and it looks like a good option for me so I picked one up. I also need to pick up a tube of some Sashco Through The Roof sealant to help seal the pilot hole and the screw eye holes. With any luck at all, I can do the guy wire mount installations this weekend, assuming it's not too hot on the asphalt shingle roof.

 

[TimmyTheTorch]

I would have done a tuned stub at the base for lightning protection.

I will have to look that up because I don't know what it is. And yet more learning from the folks here...

 

[TimmyTheTorch]

Time to work out where to mount the guy wire anchors. I have two guy wire rings on the mast, one just below the rotor plate and one at the top just below the thrust bearing plate. Not sure if I really need two or if they're in the best spot but I have to start somewhere.

I have about 420' of 1/8", 7x7 strand, 316 stainless steel (so it says but I doubt it) aircraft cable, also turnbuckles, thimbles, etc. I'm using some paracord to figure out the guy wire lengths in hopes of measuring four or five times and cutting the actual cable just once.

Right now my plan is to have a guy wire from both the top and lower guy wire rings going to the 8' anchor post I put in the yard on the west side of the house. The height may not be ideal but I don't like the idea of decapitating someone with a low-slung wire when one of us is ripping around the yard on a snowmobile or dirt bike or four wheeler or even walking at night. I will have wires going at about a 45 degree angle from the top and lower rings to mounts in the soffits north and south of the mast. The location of the one to the north will depend on what type of job I do installing the mounts above the soffits. I figure if I make a mess of that at least the leak will be outside the house.

The pictures are looking to the east and I live on a hill with some dandy westerly winds when storms hit.

 

[linearone]

This is very ambitious to put that much stuff on top of a pole. No matter how many guy wires you have. What happened to the whole idea of the tower in the first post?

 

[TimmyTheTorch]

This is very ambitious to put that much stuff on top of a pole. No matter how many guy wires you have. What happened to the whole idea of the tower in the first post?

I had Digger's Hotline come and check the place I was planning on putting the 4'x4'x4' concrete base for the tower and found out I have both cable and electrical services running right through the dig zone. I was told I am not allowed to move the service lines myself nor can I just dig around them and encase them in concrete. I don't really have a second spot where I can get agreement within my household to put up a tower so I downsized to a 2'x2'x2.5' pad for a tilt mast base. It's probably turned into more work and expense than it would have been to stick with the tower and pay to get the services moved.

I'm making this as robust as possible with a strong concrete base, two connection points to the house and six guy wires split across two guy wire rings. If it fails, well, it won't be my first failure nor my last. I'll just regroup and move on.

 

[TimmyTheTorch]

M104C assembly done. Family stuff the rest of the day so measurement/alignment tweaking and tuning time with the beam and V58 above it tomorrow. It's getting into the upper 80s and humid here today, plus air quality advisory due to the smoke from the Canadian wildfires so my motivation for outdoor work is slim to none.