Seeking VHF and Shakespeare ART-3//ART-2 guidance

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williamabernathy

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Hi, all. I'm hoping the radio techs out there can help with this.

When I key the mike on Channel 26 for the Sea Tow automated radio check (11.3nm away, mostly over land), it always triggers the Sea Tow response. My voice in the reply message is sometimes faint-but-clear, other times barely audible, other times not audible at all. So I'm thinking of checking my output with a Shakespeare ART-3 or ART-2 tester.

Radio is an Icom M302 on an 8' antenna (sorry, can't recall the brand).

First question is the difference between the two testers. Seems that the ART-2 tests just transmission, whereas ART-3 also tests reception. I'm satisfied with my reception, though. It's the transmission, standing wave, etc. that I'm interested in checking. So the ART-2 would appear to suit my needs (and it's cheaper) -- presuming an ART-2 is worth a hoot in the first place.

Second question is whether I even need to test. If I am reaching 11+nm (but with varying clarity), should the signal be good enough? Do I need to test the SWR to confirm proper output?

Thanks for any comments. They're most appreciated.

V/R
 
I'm sure BillyIII is donning his red cape &will have your answer faster than you can say speeding bullet!
 
It sounds like you may have an audio problem, neither tester will help if that is the case? However 11 miles if the path is obstructed could cause the condition you are describing. If you have a spare handheld or radio listen to your own audio (careful watch for feedback) and see if it is crisp and clear all the time.
To check your receiver sensitivity tune into various NOAA weather stations and see how they sound.
Since there are no adjustments that can be made to VHF marine antennas they are either good or bad I wouldn't waste my money on either tester. If you suspect a problem the 1st step for GP would be to replace the PL-259 connector and see if you have an improvement. A quick down and dirty test for a dead short would be to unscrew the connector and just place the center pin into the radio while listening to a NOAA station. Using an Ohm meter to test for a DC short is worthless on most VHF marine antennas because they are designed to be a dead short outside of the band pass of the marine antenna.
There could also be a problem with the SeaTow repeater I would listen to see over a period of time how most other stations sound through it on channel 25.
To answer your final question I think 11 miles with varying degrees of playback signal quality is pretty good. This is without me knowing the RF path loss between you and the SeaTow repeater.
Another quick and down and dirty test would be to try and hit the repeater on low power vs high power. If there is almost no difference in how the playback audio sounds you might have a power output problem with your ICOM (I doubt it).
If you are looking to verify your TX power, antenna connector and VHF antenna VSWR you only need the ART-2.
While the ART-3 is nice you really shouldn't need it.
Bill
 
If you have a bad VSWR from a bad antenna or bad antenna connector the ICOM VHF radio (most) will reduce it's power output to keep from destroying itself.
I doubt you could access or hear anything 11 miles away if you have either of the above conditions.
Bill
 
Bill,
Thanks very much for your extended reply. I appreciate your taking the time to go into that detail. Here are a few comments to add:

-- "It sounds like you may have an audio problem..."
---- I've wondered the same myself. If my carrier signal [is that the right term?] always triggers the repeater but my voice is of varying quality, then maybe my mike could be at fault. But I don't know how to test the mike.

-- "To check your receiver sensitivity tune into various NOAA weather stations and see how they sound."
---- NOAA reception is generally good. The far stations sound like far stations, nearby are stronger (kind of a duh answer, I know, but the reception seems consistent with distance).

-- "If you suspect a problem the 1st step for GP would be to replace the PL-259 connector and see if you have an improvement.
---- I will check the PL-259 and its connections. I looked recently, and it appeared ok, but I will check again (don't recall if crimped or soldered). [And GP is ground plane?]

-- "A quick down and dirty test for a dead short would be to unscrew the connector and just place the center pin into the radio while listening to a NOAA station."
---- Did that last time I was aboard, reception comes and goes crisply with the touch of the center pin.

-- "To answer your final question I think 11 miles with varying degrees of playback signal quality is pretty good. This is without me knowing the RF path loss between you and the SeaTow repeater."
---- Good to know that 11nm is pretty good. Land between me and the repeater is lowland, marshy with trees, if that matters re: RF path loss.

-- "Another quick and down and dirty test would be to try and hit the repeater on low power vs high power."]
---- Tried that, but low power (1 watt, I think) did not trigger the repeater.

There's another SeaTow repeater in the area (lower Chessie) about 9nm away. I haven't tried that yet but will.

Thanks again, very much, for your help.

V/R
Bill
 
quote:
Originally posted by williamabernathy

Bill,
Thanks very much for your extended reply. I appreciate your taking the time to go into that detail. Here are a few comments to add:

-- "It sounds like you may have an audio problem..."
---- I've wondered the same myself. If my carrier signal [is that the right term?] always triggers the repeater but my voice is of varying quality, then maybe my mike could be at fault. But I don't know how to test the mike.

-- "To check your receiver sensitivity tune into various NOAA weather stations and see how they sound."
---- NOAA reception is generally good. The far stations sound like far stations, nearby are stronger (kind of a duh answer, I know, but the reception seems consistent with distance).

-- "If you suspect a problem the 1st step for GP would be to replace the PL-259 connector and see if you have an improvement.
---- I will check the PL-259 and its connections. I looked recently, and it appeared ok, but I will check again (don't recall if crimped or soldered). [And GP is ground plane?]

-- "A quick down and dirty test for a dead short would be to unscrew the connector and just place the center pin into the radio while listening to a NOAA station."
---- Did that last time I was aboard, reception comes and goes crisply with the touch of the center pin.

-- "To answer your final question I think 11 miles with varying degrees of playback signal quality is pretty good. This is without me knowing the RF path loss between you and the SeaTow repeater."
---- Good to know that 11nm is pretty good. Land between me and the repeater is lowland, marshy with trees, if that matters re: RF path loss.

-- "Another quick and down and dirty test would be to try and hit the repeater on low power vs high power."]
---- Tried that, but low power (1 watt, I think) did not trigger the repeater.

There's another SeaTow repeater in the area (lower Chessie) about 9nm away. I haven't tried that yet but will.

Thanks again, very much, for your help.

V/R
Bill

Click to expand...

I will try to answer the questions and your comments in order.

-- "It sounds like you may have an audio problem..."
---- I've wondered the same myself. If my carrier signal [is that the right term?] always triggers the repeater but my voice is of varying quality, then maybe my mike could be at fault. But I don't know how to test the mike.

You could be at the repeaters open squelch threshold at times. VHF signals that are not line of sight tend to vary especially when using FM (frequency modulation)as the transmission mode. The repeaters discriminator level might at times not have enough signal from your VHF radio to pass audio. I'm pretty sure your problem is not a problem just a symptom of not being line of sight to the repeater. I suggest monitoring that SeaTow repeater and seeing if others seem to have the same problem? It sounds like the repeater is being heard what I would call dead full quieting. This is where the repeaters TX carrier with no audio or audio has no hissing background sound. I have seen VHF radio microphones (especially Garmin's) have intermittent audio caused by placing one's finger over the small hole (microphone) by holding the mike improperly or because a drop of water got into the mike element. If it's water it can be cleared using a can of compressed air or blowing into the mike element's hole. Most VHF radios use electret condenser style mike elements. These are real small and easily blocked. The larger grill is usually the remote speaker even though many people think it's just a microphone. To test the mike borrow a handheld and listen to yourself or if you have a slip neighbor simple ask him to do a few tests with you. You want to have excellent signal when you check the microphone. In the past some FM transmitters had the TX audio (or it's TX frequency deviation) set too low or high this can mimic the symptom you describe but I really doubt that you have a problem.

-- "To check your receiver sensitivity tune into various NOAA weather stations and see how they sound."
---- NOAA reception is generally good. The far stations sound like far stations, nearby are stronger (kind of a duh answer, I know, but the reception seems consistent with distance).
-- "If you suspect a problem the 1st step for GP would be to replace the PL-259 connector and see if you have an improvement.
---- I will check the PL-259 and its connections. I looked recently, and it appeared ok, but I will check again (don't recall if crimped or soldered). [And GP is ground plane?]

This pretty much clears your VHF radio and antenna of having any receiver or antenna problems. At this point if you really wanted to dig into this to satisfy your curiousity the ART-2 would help verify the VHF antenna, cable and connector are good (VSWR) as well as your transmit power. However I think by the results of this test your receiver and it's antenna system are working properly.

GP I meant good procedure, most VHF marine VHF antennas use no ground plane.

-- "To answer your final question I think 11 miles with varying degrees of playback signal quality is pretty good. This is without me knowing the RF path loss between you and the SeaTow repeater."
---- Good to know that 11nm is pretty good. Land between me and the repeater is lowland, marshy with trees, if that matters re: RF path loss.

-- "Another quick and down and dirty test would be to try and hit the repeater on low power vs high power."]
---- Tried that, but low power (1 watt, I think) did not trigger the repeater.

I think given all the information and test results the probability of you having a problem with your VHF marine system is low.

The really unknown variable to me is your TX audio circuit which includes the microphone. Again this could be simply the way you are grasping the mike. Look real careful at the mike you should see a small hole in the front that is not under the grill, make sure your fingers don't block it.

I would be curious how the 9nm repeater plays back your transmitted signal. Also what the path is between your vessel and the repeater location.

Bill
 
Bill,
Yes, it could be how I am grasping the mike. I have seen that little hole and figured that was the microphone itself, versus the small speaker in the mike unit. I will pay more attention to how I hold the mike.

The 9nm SeaTow repeater is directly across the Chessie, about 95% open water. I definitely will check that next time I am aboard, and I will check my audio using my handheld vhf as you suggest, too. (I guess I had ground plane on my mind from my days with Uncle's Army, when we used OE-292 antennas, before the OE-254's took the 292's place.)

Thanks again for your advice.

V/R
Bill
 
VHF antennas with the exception of the few sold that have a base load and a steel whip (they look like they belong on a car) are the only antennas that require a ground plane. I have seen these used on many sail boats most are properly mounted on the Aluminum mast. All other VHF marine antennas are of co-linear design and require no ground plan, as an example a 5/8th's wavelength co-linear antenna doesn't require a ground plane. These produce real world gain not 2-3dbi or 0dbd but claims are anywhere from 6 to 9dbi. Almost all antenna manufactures use dbi because it inflates the gain number for sales and marketing.
Bill
 
Is one pl 259 connector better than another? I need to buy a few and the price varies.

Billy K.
 
Actually PL-259 connectors are not created =. I suggest the gold plated solder type. If you have the proper crimp tool RFS makes a good male PL-259 for RG58U or RG8X type cable.
I am partial to the Shakespheere Gold solder type with the proper shield reducer.
Bill
 
Bill A- I think your thought on the difference between the ART-2 and -3 may be a little a little incorrect. As I understand it, the main and possibly only difference is the ART-3 has the added function of being able to test and display transmit output power in detected wattage. That was an interestingly substantial enough upgrade for me to purchase the ART-3 for personal use when it came out even though I already had the -2. But you may simply be concerned with the connector , cable and antenna radiator questions.

http://shakespeare-marine.com/shakespeare-style-art-3

I'll also note as I have before, even though my head says a solid solder PL-259 connection should be better and more reliable , the reality for me as strictly an amateur is even though I can easily make reliable wire to wire or component to board solder connections, I'd judge my ability to make perfect and definitely reliable soldered PL-259 connection at closer to 50% odds . Too many times either there was too little heat to really correctly bond to the thicker male metal tube-pin, or just a bit too much heat melting some of the insulation, and annoyingly often errant solder to inhibit use of the connector. I've had to cut off a lot of new soldered connectors and re-do.
Certainly that would not be the case for a pro or others who do that job a lot more often than a lot of the rest of us.

As I've posted a few times before at least, for people like me the alternative Shakespeare gold-plated CenterPin solderless PL-259 connector is very easy and fast and works great with very good reliability as long a few precautions are taken.

Before installing the Centerpin connector I apply a light coating od silicone dielectric grease to the square-cut end of the coax and to the coax insulation which will be covered but the connector including where the piercing fingers get inserted. No cutting back insulation or trimming the braided shield mesh involved at all.(yea!) The gold-plating is wonderful for preventing corrosion of the connector, but the dielectric grease helps prevent exposure and corrosion of the coax conductors.
Then, after all parts are in position over the coax, I use slip-joint pliers to only gradually press the opposing piercing fingers a little bit at a time all the way around all pairs of fingers and around again, until all fingers are firmly and equally pressed in correctly (don't try that in one pass as that can keep some of the fingers stuck out too far to not pierce the shield conductor correctly and possibly impede screwing on the final jacket. Very very easy if done gradually.

After everything is screwed together I finish with some wraps of the now common self-amalgamating tape ( like Rescue tape) over the Stationary coax end of the connector and a bit of the coax for better seal.

I used 3 of the gold-plated Centerpin PL-259-CP-G (and a PL-258-CP-G female/female splice) connectors on my VHF antenna cable 4 years ago and still get a calibrated ART-3 VSWR reading of about 1.3 . That includes the PL-259/PL-258/Pl-259 splice about 6 inches from the base of my antenna , in order to facilitate required annual antenna removal just prior to winter shrink-wrap. That splice is add'ly fully wrapped with that white self-amalgamating tape for extra protection from weather and all the salt spray.

This is just offered in support of the very easy Centerpins as a pretty worthy alternative to solder-type for a lot of us amateurs and I bet some of the local pros have gradually come around to using them at least some of the time as well.

http://shakespeare-marine.com/shakespeare-style-pl-259-cp-g
 
Sandy it sounds like these work well for you. They aren't that difficult to work with. I actually prefer for my own use the RFS crimp style connectors. I agree with the self volcanizing tape to seal the moisture out. The only problem I have with the crimp connectors is getting the center conductor small wires all in the small hole at the end of the connector. One strand not properly located will create a dead short.
What ever works for the individual is my thought when making VHF antenna connections.
Bill
 
Thanks, I don't have the crimp tool needed, so I will get the shakespeare gold.

Billy K.
 
quote:
Originally posted by Billylll

Sandy it sounds like these work well for you. They aren't that difficult to work with. I actually prefer for my own use the RFS crimp style connectors. I agree with the self volcanizing tape to seal the moisture out. The only problem I have with the crimp connectors is getting the center conductor small wires all in the small hole at the end of the connector. One strand not properly located will create a dead short.
What ever works for the individual is my thought when making VHF antenna connections.
Bill

Click to expand...


Bill- I've never tried the type of crimp connectors you prefer but I will take a look at those and the crimper. My electrical ratchet crimper does have 4 or 5 dies(?)stored on the handle so perhaps one might even be appropriate?
But for me and my personal happy results so far (only on maybe 7 or 8 connector replacements at most over the years for friends and myself , it's hard to beat the self-centering , no cable-trimming-whatsoever ease of the Centerpins with the DE grease and tape.

The 1st one I tried was a flub, however, because I pressed the fingers all the way down in one pass to end up compressing the coax unevenly, and learned from that mistake.

I'm just a dabbling boater and would never pretend to be 1/1000 as knowledgeable about electronics and "related stuff" as you are. Heck , I wish I could understand more than a small fraction of the great wireless access and related info you provide for bigger heads than mine, so I'll sneak in thanks for all your expert forum help.
 
Be cautious when choosing a crimp tool. Radio Shacks version only does RG-59U and RG-6, it doesn't do RG-58U or RG-8X.
As far as LMR-400 or aka 9913 Belden these are specialty crimpers. If anyone really needs to borrow a set let me know and as long as you pay for shipping I'll lend some spares out.
It's not wise to use 75 ohm RG-59 or RG-6 crimpers on 50 ohm cable like RG-58U or RG-8X. The crimp tool for the 75 ohm style cable and connectors are too large and will not provide a good or proper connection.
Also L Comm sells the proper crimp tools and connectors or they can be found on E-Bay for real bargains.
Bill
 
I borrowed a shakespeare Art 2 antenna tester (thanks Walter). I have three antennas each one read about 1 on the power test. On the adj. check I couldn't get the meter near the blue to check the vswr correctly. Am I doing something wrong or are all three antennas no good, or do I need a new radio?

Billy K.
 
quote:
Originally posted by BillyK

I borrowed a shakespeare Art 2 antenna tester (thanks Walter). I have three antennas each one read about 1 on the power test. On the adj. check I couldn't get the meter near the blue to check the vswr correctly. Am I doing something wrong or are all three antennas no good, or do I need a new radio?

Billy K.

Click to expand...
BillyK might be a stupid question what channel did you try this on? If channel 13 you are only putting out 1 watt. If the VHF radio was set to low power again you only have 1 watt of output power. It's not enough for the tester to work. However if you had the radio in the high power mode on say channel 9 you should have 25 watts of output power and it would seem that your radio might be defective.
Bill
 
Thanks Bill, I used 22 but I will try 13.

Billy K.
 
quote:
Originally posted by BillyK

Thanks Bill, I used 22 but I will try 13.

Billy K.

Click to expand...
BiilyK, don't use channel 13 your radio will only output 1 watt! Please try channel 9 and make sure the radio is on "HIGH POWER". I believe that test unit needs your VHF radio to be on high power channel 13 by default is a 1 watt channel on the other hand channel 9 can be either a 1 watt or 25 watt output channel.
Bill
 
Obviously I need to work on my reading comprehension, thanks Bill channel 9 it is.

Billy k.
 
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