You could be running way too much power if

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67Dart273

67Dart273

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Your antenna tuner needs a switch this big

s-l16001.jpg


Just bought this off ebay for 80 bucks shipped from someone overseas. I intend to make a remote motor tuned antenna tuner/ matchbox / coupler and put it up on the tower. This switch will select inductance and will use a big vacuum variable for the capacitor. I've already got some of those

jennings-vacuum-variable-capacitor-model-ecs-30-10s_252360381212.jpg



This will allow coax which is noise shielded to feed up to the box, yet allow "all band" tuning 'up there.' The problem with a ladder line / balanced line fed antenna now is, "it ain't balanced." This is because with metal roofs, neighbors, power lines, and all the rest of the junk, there is no possible way to actually "balance" a "balanced" antenna, ant THAT causes the feedline to pick up noise and trash

doubletdiagram.gif
 
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I knew a guy years ago who had an 11 meter amp with one BIG tube in the center. I would "guess" it was about 6" in diameter and 8" high. When it was cold out, there was no need to run the heater in that room.
 
That's just one of those little music mechanisms from a music box that you blew up so it looks big. :D
 
yeah, this looks like where ill find my answer

so I bought this boat and it came with a marine radio (which is just fancy words for a CB)
it had the antenna installed, but not the radio
(absolutely hilarious, someone paid for overnight shipping on this radio, which has been in the cubby of the boat since 1996)
anywho, I got the whole deal hooked up and wired in BUT there is no plug on the antenna
it looks like it is just a plane ole coax wire, and it needs one of the plugs that has the jagged teeth on it, like a crown
I'm sure if you've ever seen one you know what I mean

any idea where I can find one?
just that plug?
 
Actually, marine VHF is not CB. LOL. You are probably talking about what is known as a UHF connector, which is used on CB radios? So the radio looks like this?

s-l300.jpg


Now the male end must fit (be made for) specific coax cable types and there "are a few." RG-58, RG8, and others look on the coax and see if it's lettered, or look in the destructions for the antenna if you have them.

If that all fails post a photo of the cable, and an accurate caliper of the OD of the cable.

And, there are variations on them, IE old school solder on, crimp on, solderless, and lower quality like Radio Shack sells.

Marine 16 channel is VHF, so you want a good quality set up for the antenna and coax and connections.

This is one type of "decent" UHF connector, crimp the shield, and solder the center:

mw15PwNEKGYH5YRUnEde4Xw.jpg


This is the "root original" of this connector, known as a PL-259, made for the military around WWII. All other types are incorrectly called that, more correctly a UHF connector. These originally soldered onto the "big" RG-8 cable "back then" in the 40's

image001.jpg


The little bushings shown below, came "after" the original above. These are used to install RG-58 or RG-59 into the original type connector. There WAS NO small cable when the original connector was first produced

image002.jpg
 
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This shows some of the steps to install the large, original type RG-8, or on the right the smaller RG-58/ 59 into an original type PL-259 plug

pl259_coax.jpg
 
67Dart273 said:
That there would work for HF (CB and lower freq) but that is NOT how it's done for VHF. Marine is VHF, up in the 155mhz range, and deserves 'correct' work.
Click to expand...

You just think because it's for a marine and a possible emergency device that it needs to be good quality and reliable. :D

JK, LOL
 
Here's a true story............in my days working for Motorola, some of the upgrades in the dispatch centers take time, and there is "overlap" where old equipment gets left until it can be removed, etc, as new stuff gets online.

Up in Newport, WA (Pend Oreille County) I got in "late to the party" to such goins' on's. We had severall little interesting "times" up there

wa26911.jpg


At any rate at one point I was up on a ladder, up in the drop ceiling, pulling out some unused controls, low voltage, and telco cables from the old system, when I encountered a piece of coax that didn't want to "move smoothly." It started to pull out with some of the other cables and when "it came" "there it was"

Some worker, sheet metal, plumber, ?? who knows, had CUT the coax somehow, probably with an errant saw, and had doubled the coax back on itself and SPLICED IT BACK TOGETHER with WIRE NUTS

This was on a 450mhz (UHF) radio so the fact that it "evidently" still worked was nothing less than a small miracle. Some radios, by the way can fail the PA with such things as high feedline SWR

That was not the only issues at Newport!!!! The building had been remodeled, probably more than once, and contained the dispatch center, the Sheriff's offices, and the JAIL. There was a phone room which ended up INSIDE the general part of the jail.

The doors had electric locks, and there was an intercom. There was a telco guy, and two of us from Motorola doing some work. There was someone else doing tests on the emergency generator.

The backup power is supposed to be prioritized.....The stuff that HAS to work for 911 is on a UPS, and it's backed up by a generator. So they were "testing" all this.

Turns out the jail locks and intercoms WERE NOT on the backup generator. So there we were, in the telco terminal room, BLACKED OUT. The only thing either of us had for a light was my "Mini mag" thank "gosh." So we pawed around with a butt set until we got an outside trunk, then called BACK INTO the SO to have them send a human jailer in with a good old KEY.

The side note? The coffee pot and the light over the pool table in the lounge WERE ON THE GENERATOR!!!!!
 
67Dart273 said:
Actually, marine VHF is not CB. LOL. You are probably talking about what is known as a UHF connector, which is used on CB radios? So the radio looks like this?

s-l300.jpg


Now the male end must fit (be made for) specific coax cable types and there "are a few." RG-58, RG8, and others look on the coax and see if it's lettered, or look in the destructions for the antenna if you have them.

If that all fails post a photo of the cable, and an accurate caliper of the OD of the cable.

And, there are variations on them, IE old school solder on, crimp on, solderless, and lower quality like Radio Shack sells.

Marine 16 channel is VHF, so you want a good quality set up for the antenna and coax and connections.

This is one type of "decent" UHF connector, crimp the shield, and solder the center:

mw15PwNEKGYH5YRUnEde4Xw.jpg


This is the "root original" of this connector, known as a PL-259, made for the military around WWII. All other types are incorrectly called that, more correctly a UHF connector. These originally soldered onto the "big" RG-8 cable "back then" in the 40's

image001.jpg


The little bushings shown below, came "after" the original above. These are used to install RG-58 or RG-59 into the original type connector. There WAS NO small cable when the original connector was first produced

image002.jpg
Click to expand...

that is exactly what it looks like
the guy who owned the boat before me had installed the antenna, but not the radio, so I don't have paperwork on that

I will run out later and check the cable for markings and report back


thanks guys
 
When did MW navigation radio stop?
My father got a "marine band" radio in the late 60s, and the radio was sensitive, but great lakes cargo boats must have already gone to VHF by 1970.
 
When I was the chief engineer for the KC-10 bed down at McGuire AFB, my hydrant refueling contractor was cutting up unused wires and cables from a manhole on the aircraft ramp and he saw 4 newish 3/4" coax cables that were tagged for removal. The contractor said to himself "these cables look like they're new, so maybe somebody made a mistake in tagging them". So he cut and carefully spooled them up just incase. Well when he cut them, he saw sparks flying, but he continued. That‘s when the guys in the RAPCON watched their scopes go black! Holy crap! McGuire was the FAA's handoff between Baltimore and NYC if I recall correctly. So all commercial aircraft had to immediately be rerouted around our zone - yikes! So after four hours of black screens, the Comm guys tracked the trouble down to our cut coaxes (the two main and two backup radar lines). (It was the same Comm guys who tagged the cables in the first place.). Well we repulled the cut cables and I called the FAA center in Pomona NJ to borrow some coax splices. When I turned them over to the Comm guys to install (the splices) they didn't know how to do it. Well, from my GWEN days at RCA/GE I had official Andrews connector installation training, so I jumped down into the dirty manhole in my business suit with one of the comm guys and I trained him how to do one. Then I had him jump into the other manhole and train another guy to do it (these connectors take about 15 minutes each to install), while I had another Comm guy join me in my manhole and I trained him how to do it too. When we fired up the radar, it came right back up. The wing commander was worried that he would be fired after that fiasco (he wasn't). Oh, those were fun days!
 
I once had to set up a coax link using RG-92, but the customer had pulled something huge like RG-15.
Wrong size AND impedance.
Made up matching transformers and adapters, still not good enough.
Following ancient and mysterious training from radio school, I eliminated the xformers and tuned the mismatch by pruning the length to meet the installation then solder finished the terminations. I did not need to use a stub.
 
I could almost put on Kings brand screw type connectors with my eyes closed.

As a corollary, I offer:
You may have too many records if you can no longer get at transmitter.

Universal NBFM trans.jpg
 
i just checked the antenna, it said RG-58 B R B on it
soooo, what connecter do i need and where do i buy one?
 
You need a UHF connector specified for RG-58. If you don't have the correct crimper, you need the old style PL-259 and the appropriate adapter bushing, OR you need some sort of solderless screw together connector. THAT IS WHERE things get muddy, because some of those are VERY poor quality.

This is one type that does not require a special shield crimper:

http://www.amphenolrf.com/downloads/dl/file/id/19

Amphenol 83-58FCP

https://www.google.com/search?num=2...j1.3.0....0...1c.1.64.serp..0.0.0.ZP-wcslS90E

I don't know if RF parts has a min order.....

83-58FCP-RFX UHF Push On Connector, Cable Types: RG58, LMR195,Cable Group: C, Amphenol/RF
 
thanks

ill see if i can find one of those push-ons somewhere (RF has a minimum order amount in dollars)
 
Google the part no. You might find another distributor. There are probably hundreds of differnent types. SOMEbody made (a UHF connector) one that went together mechanically like a BNC/ N connector I tried to find them for sale and could not. This is how the original type BNC went together.....mechanical compression, with the center pin soldered

bnc.png
 
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