Author Topic: Can I shorten the cable on a new Digital antenna?  (Read 440 times)

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Offline Markshoreline

Can I shorten the cable on a new Digital antenna?
« on: April 18, 2017, 06:01:46 PM »
I have pulled out the old crappy antenna mounted to the side of the cab and bought a new Digital brand to mount up on the roof rail to get better range.  I don't need the excess cable, how can I shorten it since the end is factory installed?
How would I know the optimum length to trim it to, as GregE suggests tuning it by cable length?
« Last Edit: April 18, 2017, 06:25:02 PM by markshoreline »
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Offline GregE

Re: Can I shorten the cable on a new Digital antenna?
« Reply #1 on: April 18, 2017, 06:22:48 PM »
Also, antennae wire length is part of the tuning.  Check before cutting......
Greg
Osprey 26 LC Kodak;  Arima SR 19 HT; SL 22 Honda 225
http://www.sagecreekforums.com/phpforum/index.php
Sold:  Arima SE 16 WeeBait; SH 15 WeeBoat;
SR 21 NoBait;  SL 22 ReBait

Offline fishmiester

Re: Can I shorten the cable on a new Digital antenna?
« Reply #2 on: April 18, 2017, 06:24:13 PM »
Mark: Is there any way you can coil up the excess cable and tuck it out of the way? I would not recomend cutting the cable to shorten it. I am not familier with the digital antenna, but normal vhf antennas rely on the length of the cable to keep the vswr down thus keeping the antenna tuned. Maybe Streamfixer will chime in on this and can explain it better.
If it swims, Ill  chase it
84 17' Seachaser, 2010 90hp Tohatsu tldi, BF15 Honda Custom welded kicker bracket.#lovethisboat

Offline Markshoreline

Re: Can I shorten the cable on a new Digital antenna?
« Reply #3 on: April 18, 2017, 06:26:03 PM »
Yep, I've got lots of cables coiled up in the boat!  I could do this one, too If I need to.
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Online Croaker Stroker

Re: Can I shorten the cable on a new Digital antenna?
« Reply #4 on: April 18, 2017, 07:11:28 PM »

Did you read the Digital antenna instructions?
1987 - 17' Sea Pacer - 2004 Evinrude 90 E-tec
15' Sea Sprinter - **SOLD**

"If a fish will, he will… if he won't, he won't… and that's about it… except… he may take this when he won't take that."

Offline DevMah

Re: Can I shorten the cable on a new Digital antenna?
« Reply #5 on: April 18, 2017, 08:08:50 PM »

We don't cut them but roll them up as they use low loss cable on the digital antenna.

The cheaper fibres glass ones don't have the ends connected, so we usually pull the cable and leave a few feet coiled up.


Dev.

« Last Edit: April 18, 2017, 08:37:36 PM by DevMah »
2015 21' Sea Ranger
2015 Yamaha F150
2013 Mercury 9.9 Bigfoot 4 blade
2012 Lund 1650SS  w 2012 60HP Mercury-Sold

Offline Threeweight

Re: Can I shorten the cable on a new Digital antenna?
« Reply #6 on: April 18, 2017, 10:18:20 PM »
Digital-brand antennas are tuned to the length of the cable they ship with.   If you want to match the factory performance after your cut it, it has to go to an electronics shop with a SWR meter and have it re-tuned.

Plus if you cut it, you lose the sweet gold-plated connector Digital uses, and will have to install a crappy Shakespeare crimp-on or solder-on which is much more prone to problems.

Do not coil it into a tight circular pattern either, if you can avoid it.  Coil the excess in a messy figure 8 pattern, or if you must loop make the loops large (like 12+ inches) and a little random/messy in size.  Tight coils distort the cable and cause impedance.

Former Sea Chaser 17 owner
Wild Card, Hewescraft Ocean Pro 220, Honda 225 and 9.9

“Never turn your back on fear. It should always be in front of you, like a thing that might have to be killed.”
       --- Hunter S. Thompson

Offline Markshoreline

Re: Can I shorten the cable on a new Digital antenna?
« Reply #7 on: April 19, 2017, 08:16:30 AM »
OK, thanks- I'll save some trouble and hopefully have a better performing antenna!


Did you read the Digital antenna instructions?

Croaker, you are beginning to sound like my wife...   :jester:
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Online Croaker Stroker

Re: Can I shorten the cable on a new Digital antenna?
« Reply #8 on: April 19, 2017, 10:05:59 AM »

It was a rhetorical question.  😜
1987 - 17' Sea Pacer - 2004 Evinrude 90 E-tec
15' Sea Sprinter - **SOLD**

"If a fish will, he will… if he won't, he won't… and that's about it… except… he may take this when he won't take that."

Offline Markshoreline

Re: Can I shorten the cable on a new Digital antenna?
« Reply #9 on: April 19, 2017, 11:12:25 AM »
I thought so- that was such an inappropriate question!   :jester:
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Offline StreamFixer

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Re: Can I shorten the cable on a new Digital antenna?
« Reply #10 on: April 19, 2017, 08:46:35 PM »
Mark (and others with excess antenna coax  length)

Do not coil the extra antenna feed coax.  Doing so creates a 'choke' that modifies the antenna tuning.  Rather than coiling the excess, I suggest you run it back and forth to use up the length, or just about any other form except a coil.  If you must coil it, try to stay at about a foot diameter (or larger).  If you MUST make smaller coils, don't have more than three coils at any given point.  For example,  Three coils just inside the wall, three coils a couple of feet away, three coils at the back of the radio.  Maximum 2 coils even better


StreamFixer
'97 19SC w/ Salt Boss Top
'03 Yamaha 115 EFI
'05 Yamaha T8 Solas 4 blade prop

"By the grace of God we travel upon the rivers and sea..
They, like He, are mightier than me."  Mike Jesperson aka 'Nalu'

Offline Yachter Yat

Re: Can I shorten the cable on a new Digital antenna?
« Reply #11 on: April 20, 2017, 05:00:06 AM »
   I thought about getting one of these some time ago.  From what I read, it sounds like a PITA.   Guess I'll keep my old Shake.

Yat
Dear Arima:  Stretch the Hunter platform by 5. Next, stretch the Explorer by 9 and steal 2 or 3 from the cabin.  Please hurry, I'm getting old.

16 SC/Honda 60

Offline Threeweight

Re: Can I shorten the cable on a new Digital antenna?
« Reply #12 on: April 20, 2017, 10:29:12 PM »
No more a pain than your old Shakespeare.  If you left the Shakespeare cable full length, the Digital would have greater signal clarity and range, plus much sturdier construction.  If you cut it and crimped or soldered the cable, the Digital would have MUCH greater signal clarity and range, plus sturdier construction. 
Former Sea Chaser 17 owner
Wild Card, Hewescraft Ocean Pro 220, Honda 225 and 9.9

“Never turn your back on fear. It should always be in front of you, like a thing that might have to be killed.”
       --- Hunter S. Thompson

Offline Markshoreline

Re: Can I shorten the cable on a new Digital antenna?
« Reply #13 on: April 20, 2017, 11:39:50 PM »
I'm happy to coil.  Any issues with coiling next to other coils?
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Offline Yachter Yat

Re: Can I shorten the cable on a new Digital antenna?
« Reply #14 on: April 21, 2017, 06:28:50 AM »
   Threeweight;   I've been running my Shakespeare 5225 for years with (what I think, at least) a fair amount of success.  That said, you might be talking me into this.  Given what I'm reading, I'd be leaning toward cutting that cable.  Gonna have to do a little more research on this, I guess.  These days, it's like, any equipment I contemplate changing seems to be a bit more complicated than the original.  Oh well.......looks like I'll be going for my Doctorate in antenna technology.  :jester:

Yat
Dear Arima:  Stretch the Hunter platform by 5. Next, stretch the Explorer by 9 and steal 2 or 3 from the cabin.  Please hurry, I'm getting old.

16 SC/Honda 60

Offline StreamFixer

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Re: Can I shorten the cable on a new Digital antenna?
« Reply #15 on: April 21, 2017, 07:41:17 AM »
I'm happy to coil.  Any issues with coiling next to other coils?

Keep a foot or so between the coils, otherwise you might as well just make one coil and accept the signal loss.  PITA, I know, but that is the way antenna systems work.

StreamFixer
'97 19SC w/ Salt Boss Top
'03 Yamaha 115 EFI
'05 Yamaha T8 Solas 4 blade prop

"By the grace of God we travel upon the rivers and sea..
They, like He, are mightier than me."  Mike Jesperson aka 'Nalu'

Offline Yachter Yat

Re: Can I shorten the cable on a new Digital antenna?
« Reply #16 on: April 21, 2017, 09:53:18 AM »
   Hey guys;  I believe I asked this once before, but still wonder if this antenna could be ordered from the factory with a specific cable length and tuned accordingly?? :shrug9:  If this could be done, I'd be very interested.

Yat
Dear Arima:  Stretch the Hunter platform by 5. Next, stretch the Explorer by 9 and steal 2 or 3 from the cabin.  Please hurry, I'm getting old.

16 SC/Honda 60

Offline ak-angler

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Re: Can I shorten the cable on a new Digital antenna?
« Reply #17 on: April 21, 2017, 10:53:31 AM »
For those on the fence... I absolutely love the Digital antenna I installed on my Cape Cruiser. Reception is orders of magnitude better than I had with my previous Shakespeare antenna (don't know the model #). As far as dealing with the excess cable length goes (I know this probably won't help on most Arimas), I strung it back and forth in kind of a lazy figure-8 pattern, probably about 4-5 feet long, on the shelf above the window. Maybe it would work to loosely attach the excess up under one of the shelves on the sides of the cabin with a few of those zip-ties that have mounting holes? Just screw them to the bottom of the shelf and secure the cable up out of the way. Maybe...?
1985 Sea Ranger 17 Skiff Top with 2012 Suzuki DF90A

2007 Cape Cruiser Marinaut 26 with twin 2006 Honda BF90's

Online Croaker Stroker

Re: Can I shorten the cable on a new Digital antenna?
« Reply #18 on: April 21, 2017, 11:11:01 AM »
I agree with AK. My new digital seems to work great without cutting. I also hanked my excess wire in three foot figure eights and zip-tied.

(Shall I mention again how much the Standard Horizon amplified speaker helps with reception of (hearing) weak signals ?).  The speakers in most VHF radios suck.

Back in the day, I always matched my antennas using an SWR meter. Took a while by cutting one inch off the wire, soldering the connector, then checking the SWR. Then repeat until you reach a satisfactory reading. If I remember correctly, the wave length was about 36 inches ? (Been a long while)

So many posts on the internet saying that this is un-necessary these days because of advancements in the newer radios....??  (Then why does Digital recommend not cutting the cable.).  :shrug9:
« Last Edit: April 21, 2017, 11:22:46 AM by Croaker Stroker »
1987 - 17' Sea Pacer - 2004 Evinrude 90 E-tec
15' Sea Sprinter - **SOLD**

"If a fish will, he will… if he won't, he won't… and that's about it… except… he may take this when he won't take that."

Offline Threeweight

Re: Can I shorten the cable on a new Digital antenna?
« Reply #19 on: April 21, 2017, 11:56:00 AM »
Yachter, you could be anal like me and run 2 vhf fixed mount radios.  When I haggled on my new boat, I got the dealer to throw in an cheap Cobra radio + Shakespeare antenna.  It is now my backup, mounted up to one of my overhead shelves and stays tuned to the local fishing channel.  My Standard Horizon + Digital 529 combo is my main, mounted to my dash and tuned to scan 16+22+commercial traffic.
Former Sea Chaser 17 owner
Wild Card, Hewescraft Ocean Pro 220, Honda 225 and 9.9

“Never turn your back on fear. It should always be in front of you, like a thing that might have to be killed.”
       --- Hunter S. Thompson

Offline Yachter Yat

Re: Can I shorten the cable on a new Digital antenna?
« Reply #20 on: April 21, 2017, 12:48:24 PM »
   Threeweight;   I guess it was the first line of your post (suggesting these antennas were tuned to the cable they're shipped with) that got me wondering whether or not they could be special ordered, tuned to a specific cable length.  I suppose the best way to find out is to go directly to the manufacturer.   BTW, I've always been a big Icom fan boy.  Still running my old M56 from 1994.  Seems to be holding out okay...........knock on wood.  :biggrin:

Yat
Dear Arima:  Stretch the Hunter platform by 5. Next, stretch the Explorer by 9 and steal 2 or 3 from the cabin.  Please hurry, I'm getting old.

16 SC/Honda 60

Offline Threeweight

Re: Can I shorten the cable on a new Digital antenna?
« Reply #21 on: April 21, 2017, 02:09:28 PM »
Icom makes great stuff.  Check out the helm of any Coast Guard, commercial fishing, search and rescue, etc... boat, and the radio will be Icom.

I like Standard Horizon because they are a bit cheaper, and they have a stellar reputation for standing behind their products.  They also tend to roll out new technology a little bit quicker.  Their GX 1700, with it's built in GPS unit and DSC function in a super tiny package, is ideal for cramped Arima dash space.
Former Sea Chaser 17 owner
Wild Card, Hewescraft Ocean Pro 220, Honda 225 and 9.9

“Never turn your back on fear. It should always be in front of you, like a thing that might have to be killed.”
       --- Hunter S. Thompson