VHF fixed radio

[Randall Schmidt]

I googled and see Direct bury 240 on Amazon

 

[Randall Schmidt]

I take it this will work? This says both Rg8X and LMR 240, is that a problem?
Manufacturer Times Microwave
Model # LMR-240DB
Product Description 50 Ohm Coaxial Cable - Direct Burial Low Loss RG8X Cable
Cable Type 1/4" Braided
Shield % 90% Foil
Impedance 50 Ohms
VOP. 84%
Center Conductor 0.056" Solid
Insulation Foam Polyethylene
Other Spec Direct Burial
Nom. core O.D. (in.) 0.056"
Nom. O.D. (in.) 0.240"
Losses Shown are based on 100 Foot Length
loss 50 MHz 1.7 db
loss 100 MHz 2.453 db
loss 400 MHz 4.973 db
loss 900 MHz 7.6 db
loss 1000 MHz 7.985 db
Nom. Capacitance (pF/ft) 24.2

 

[Randall Schmidt]

My boat specs say I have a 40 foot clearance. My mast goes thru the cabin top down to the bilge so I'm expected that is a 40-foot run to the top where the antenna is mounted. From there it is 8 feet aft to the radio and 5 feet up. So I could do a 40 foot segment and a 13 foot segment, get four PL259 connectors and a female adapter to put 2 cables together
http://www.theantennafarm.com/catalog/terrawave-njack-njack-6007.html
They sell the cable with connectors installed. I guess that will not work since I expect I'll need to route the wire thru tight spaces I probably need to install the connectors on one end, make sense? How much extra cable should I get? I'm think 2 feet for the vertical run (mast) and 2 feet for the horizontal run. This should give me room to practice installing and possibly damaging and throwing away some of the cable ends.

 

[Don S/V ILLusion]

Where have you found direct bury?

I buy mine at Ham Radio Outlet or from Cable Experts, both of whom also sell better quality connectors. Be cautious of the source of cable from Amazon unless it is Times Microwave coax. There are imitators

 

[Davidasailor26]

My boat specs say I have a 40 foot clearance. My mast goes thru the cabin top down to the bilge so I'm expected that is a 40-foot run to the top where the antenna is mounted. From there it is 8 feet aft to the radio and 5 feet up. So I could do a 40 foot segment and a 13 foot segment

The 40' clearance is measured from the waterline, but the mast is stepped below the cabin floor boards. If memory serves the base of the mast is probably about 1' below the waterline. If it were me I'd get a 45' segment for that run.

 

[Bill Roosa]

Much of the confusion on listing that say LMR 240 (or other manufacturer designations) and RG8x is they are all RG8 cables made by other guys. Well you would not want to have plain old Rg8 when you could have that LMR240 for 50% more right? Dodge, Chrysler, Plymouth; under the skin they are all the same.

 

[Brian D]

Where have you found direct bury?

Direct bury cable is any type of cable that has a Polyethylene (PE) jacket, not a PVC jacket. Most, if not all coax has a PVC jacket. LMR-240 already has a Polyethylene jacket. However, LMR-DB cable is watertight. So if you go with standard LMR cable you are good to go.

LMR-240 Outdoor PE Black 54021
LMR-240-DB Outdoor/Watertight PE Black 54090

 

[Don S/V ILLusion]

Much of the confusion on listing that say LMR 240 (or other manufacturer designations) and RG8x is they are all RG8 cables made by other guys. Well you would not want to have plain old Rg8 when you could have that LMR240 for 50% more right? Dodge, Chrysler, Plymouth; under the skin they are all the same.

Outer braid density, type of dielectric and loss characteristics among other things vary widely between various manufacturers and types of coax. The only thing all so-called RG 8 coax has in common is impedance.

 

[Fred Villiard]

Times Microwave LMR series cables are direct burial also the foil is bonded to the to the insulation, so if you due have a damaged place in the jacket the moisture will not migrate all thru the cable. Fourteen years of running the environmental and high frequency test lab of Amphenol Interconnect Products, I've tested just about ever buddies coax. LMR wins hands down in both low loss and durability unless you go to the semi-rigid or air dielectric. There is a German company that is making a cable that is very similar to the LMR, it should be pretty good also.

I'd recommend using LMR 240UF for ease of running up a mast, 400Uf is a little stiff. what ever you do DO NOT use the Shakespeare connectors, they are pure junk, stick to silver plated solder types, unless you can get hold of the proper crimp on and the tooling to crimp them on. The proper tooling is very expensive, and none of the cheap tooling is any good.

I'll get off my horse now
Fred Villiard K3VKY

 

[jssailem]

for Ham Radio Outlet. Had LMR 400 in my local store at a good price, found it on line. I found the cable to be a bit smaller diameter than RG8. The outer coating has a rubberized feel so give it enough room in your conduit. The outer cover can get caught and bunch up if not careful. Then you can loose all the low loss function. It is also nice in that the LMR400 is more flexible than RG8. It can be bent around a tighter radius. Care in making turns is again advised. Easy to bend and damage the shielding under the cover.

Be sure to get the proper fittings for connections. I chose to run the wire straight no connectors in the mast. If I need to remove the mast I left extra wire so the wire can be cut and then connections attached when the mast is reset.

 

[bgary]

The best value quality cable is LMR type, either 240 or 400.

+1
I went with LMR-240 "ultra flex". Great stuff, the same size as the 1/4" cable you'd get at the store but much better spec, plus well protected against water and UV.
I ordered a pre-made cable from Universal Radio - http://www.universal-radio.com/catalog/cable/cable.html
ordered it longer than I needed, and cut one end off so that I could run it where I needed to. That way I had a "known good" (professionally made) connection at the top of the mast, and had a piece of cable left over (with the other connector) I could make into a patch-cable.

 

[Bill Roosa]

My preference is RG-8U foam. Pretty stiff so it stuffs down the mast well and attenuation almost the same as 240.

 

[Randall Schmidt]

I'm getting LMR240 direct bury. the PL-259 connector is listed on the seller's site as a UHF not a VHF connector. Is that an issue?

 

[jssailem]

The PL259 is correct for VHF. Get the solder type connector. Easy to do.
Here's a video for help.

 

[nameless]

LMR 240 (genuine) is superb antenna feed wire. PL259 UHF is simply a traditional term. In reality it's an HF - VHF connector. On my boat all antenna connectors are Amphenol 'N' connectors (clamp on). The final connector to the radio is a PL259 as that is what the radio is expecting. 'N' connectors are water proof but I still seal them with 3M's self amalgamating tape and a final wrap of quality electricians tape. If you use the 259's make sure they are silver plated Amphenol, the soldering is top notch, and seal the connectors completely as they are not water resistant. Hope this helps as doing it right first time saves money and aggravation down the road. Take care.

 

[Randall Schmidt]

My old VHF was mounted on the wood panel that separates the nav station from a midship berth. As such it faces aft and is hard to read w/o sticking your head into the area close to the side of the cabin - not convenient for use. My new system has LEDs that need to be seen. I want to mount it facing the center of the boat which in this case means point to the port since it mounts on the starboard side of the cabin. to do this, I'll have to mount it to the fiberglass that forms the ceiling area over the Nav station. I'm reluctant to drill holes in the fiberglass. I tried using velcro instead but that fails to hold the VHS radio in place. Do I just move ahead with a small pilot hold and use self-taping screws to mount the radio and not worry about the new holes?

 

[Davidasailor26]

No help on exactly how the fasteners should work, but here's a picture of the OEM location for an '85 model, in case that helps.

 

[Randall Schmidt]

thx
okay so it looks like they just put self tapping screws into the fiberglass and had no issue