Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-12-2015, 12:42   #1
Registered User
 
autumnbreeze27's Avatar

Join Date: Apr 2012
Location: Cruising Mexico
Boat: 50' Herreshoff Ketch
Posts: 892
Too much RX noise on HAM setup

So here's an overview of my setup, which has been discussed before on here.

I've got a IC-7200 connected to an AH-4 using the OEM cables (the entire length). The radio is mounted using the OEM hanging mount, in the center of the nav table, over the notebook. The cables run with all the other cables down to the bilge (4ft) , then outboard (2.5ft) near a black iron fuel tank with a bunch of spare wires stashed next to it, then aft (4ft) to a space behind some drawers. There the AH-4 lives, with the GTO-15 going up through the deck, held away from the spreader by 3" standoffs until it gets above the isolator to the shroud. There are 3 shrouds anchored to the same chainplate here, one a split backstay, the other 2 are mizzen shrouds (one is the isolated antenna). There is another mizzen shroud 3ft away on another chainplate. The shroud is isolated at the spreader, and isolated at the top, where GTO-15 jumps it to the triatic stay, which is isolated on both ends.

The power cable runs straight to the battery.

I've got ferrites on the power cable, the antenna control cable (at the radio).

I've got a KISS that runs off the AH-4 and then aft under some cabinets on the edge of the hull, above the waterline. It's about a foot too long for the space, so the last foot or so bends up in a u-turn.

If I turn everything off... and I mean everything but the radio and the notebook (not charging), I still get a lot of interference/noise/static. Even out in the boondocks with no cell coverage.

I've been able to transmit emails via RMS Express, but not receive.

I reset my 7200 and that seemed to help. I'm starting to wonder if either RMS Express or the Chirp software I programmed my Icom with is scrambling something. When I reset the 7200 the waterfall display in RMS Express changed, and would show the impact of the various filters. Since I had a better way to gauge the signal quality I started tweaking several things, like the mic level and rf/sql. I was able to determine I needed more insulation from my notebook, so after adding 3 more ferrites to the usb cable (that had 2 built in on each end) I had a cleaner signal, but I still have RFI issues even when the notebook is off and disconnected.

I've been able to have some success with voice, talking on the sonrisa net, but only with close strong signals. I have issues with weaker signals. Trying to talk to a buddy in San Carlos he was barely readable.

I've had better luck with RMS Express receiving emails since I added the ferrites to the PC, but it still has too much noise where sometimes I have to override the busy indicator (I can hear the channel is free) and then it connects.

So here's my list of questions, for those of you who might be willing to help me some more:
1) I am going to order a T4 isolator and put that in the system, I've been using this as a reference http://sfbaysss.org/resource/doc/Mar...ferson2014.pdf
2) I am going to order a MFJ-874 from HRO (the wife is making a supply run to the USA for Christmas) -- will this help troubleshoot?
3) More ferrites
4) I'm going to see if I can run the KISS differently, or possible add another wire and send it to the rudder or something?
5) Is the stash of wires near the antenna cable running from the radio to the tuner a problem?
6) I'm not sure if I'm getting noise from the solar panels, even if I turn them off (killing the breakers on both sides of the MPPT)
7) I'm in a slip in La Paz right now, trying to get jvcomm32 to work with weatherfax, but too much noise there too. Will try again at night to see if it makes a difference.
8) It seems like the lower freqs I have more noise on than the higher freqs

Any other tips or tricks I should try? I've been reading the regular and advanced manual for my radio, and gotten a little better with it, but I'm still having issues with RFI (I'm pretty sure)
__________________

__________________
autumnbreeze27 is offline   Reply With Quote
Old 11-12-2015, 14:30   #2
Registered User
 
autumnbreeze27's Avatar

Join Date: Apr 2012
Location: Cruising Mexico
Boat: 50' Herreshoff Ketch
Posts: 892
Re: Too much RX noise on HAM setup

I decided to poke around that Single Sailor's website some more and found a bunch of SSB/HAM documents... after reading through those I've come up with a game plan.

I'm going to try and move the tuner to a better spot higher up closer to the antenna... I was able to squeeze an extra wrap on my ferrites... and I'm going to see about rewiring the radio so it's cables are more isolated.

and order that Isolator.
__________________

__________________
autumnbreeze27 is offline   Reply With Quote
Old 11-12-2015, 14:39   #3
Registered User

Join Date: Feb 2015
Location: Oakland CA
Boat: Morgan 46 ketch
Posts: 110
Re: Too much RX noise on HAM setup

Had a bit of experience in this area myself so here are my perhaps biased suggestions:

Looks like you covered very well just about all the bases in your investigation. Couple more ideas: A portable AM radio that uses a ferrite antenna can possibly be used to find the noise source. I have old RDF radio that I have used for that purpose. And if the high noise level doesn't show up on a battery powered radio it would give you some confidence that you can eventually get good performance from your on-board rig.

Does the noise level change if you select different house battery connections?

You could try running a long wire, hoisted on a halyard, directly to the RF jack on your ICOM to eliminate any possibility of the tuner or antenna system causing a problem. I know these are very unlikely noise sources but at this point you need to get to the basics.

You said you still had excessive noise on the ICOM while in the boondocks and with all other electrical items shut off. Since you are in LaPaz I take it you mean you went away from town and out to the islands where there are no power lines. Again, compare your Icom to a cheap battery powered AM radio in the same location and tuned to the same frequency.

When you get the SWR meter, check that your tuner is working. If your SWR is high due to mismatch of the antenna, this may also show up as a high noise level on the RX compared to the desired received signal strength.

You may also be able to take your Icom ashore for a test completely independent of the boat and marina, if you have the AC power supply or want to lug a battery.

Good Luck,
Doug
__________________
waterman46 is offline   Reply With Quote
Old 11-12-2015, 16:45   #4
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 1,886
Re: Too much RX noise on HAM setup

autumnbreeze,
You presented a LOT...so this is going to take a while!!!!
(if I don't finish tonight, more later/tomorrow!)

1) First off, much of the answers to your queries are in the links in the "sticky" on the top of the Marine Electronics page, here...
Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, etc.)


2) Secondly, the definitive source for optimum installation of digital HF systems (whether PACTOR or otherwise) on-board is from Sailmail...
Please read (and download) the Sailmail Primer (which has a good deal of RFI info, as well as a LOT of other stuff that will be of help...
SailMail Primer


3) Thirdly.....
--- Please forgive my bluntness, but are you sure you are listening to RFI?? And, not natural / atmospheric noise???
(I'm sorry if this offends anyone, but the number one comment/complaint I hear from those new to HF comms, is that "it's noisy"...and many fail to understand that much of the "static" they hear is natural....and depending on the freq/band, usually is coming from 100's and 1000's of miles away...)

--- Also, make darn sure you have the IC-7200's "pre-amp" turned OFF....

--- Also, reduce the 7200's RF Gain control....

--- And, turn OFF any "noise blankers" / "noise reduction" features....(you can turn them on later, if needed....but usually they will distort the signals so much that clear reception is difficult...)


---- And then.....do NOT attempt to use a digital comm mode, before you have both learned about radio noise and have proved the radio system works on Voice (or CW), over both local/regional ranges (100 - 500 miles), typically on the lower bands....and on longer ranges (> 1500 - 2000 miles)...




4) Unfortunately, the "Universal Serial Bus" (USB) is a poor choice for use near HF comms gear....as it uses RF freqs!!
But, usually this is a cause for "transmit RFI" (RFI ingress into a computer), rather than USB-generated RFI....but, this is possible...

And, also sorry to say that I have heard reports (anecdotal) of the IC-7200 being fairly "RFI-sensitive"....(ironic as Icom originally marketed it as the rig for hams that wanted to hook a computer up to it!)



5) Once you've understood and done all the above, we should be able to narrow down your exact issue and point you in the right direction...




6) But, 'til then....here are some specifics, in red...
Quote:
Originally Posted by autumnbreeze27 View Post
I've got a IC-7200 connected to an AH-4 using the OEM cables (the entire length). The radio is mounted using the OEM hanging mount, in the center of the nav table, over the notebook.
This is all good...


The cables run with all the other cables down to the bilge (4ft) , then outboard (2.5ft) near a black iron fuel tank with a bunch of spare wires stashed next to it, then aft (4ft) to a space behind some drawers.
Not sure what other cables....but it is doubtful that any other cables are coupling enough noise into your coax (common mode) to present much of a problem....but, if you place a few ferrites on both ends of the tuner control cable and coax (and even add the "Line Isolator" as well...), you should have no issues here...



There the AH-4 lives, with the GTO-15 going up through the deck, held away from the spreader by 3" standoffs until it gets above the isolator to the shroud. There are 3 shrouds anchored to the same chainplate here, one a split backstay, the other 2 are mizzen shrouds (one is the isolated antenna). There is another mizzen shroud 3ft away on another chainplate. The shroud is isolated at the spreader, and isolated at the top, where GTO-15 jumps it to the triatic stay, which is isolated on both ends.
Although not a common approach, this should work fine for you....but..
But, make sure you have clean (RF clean) connections between the GTO-15 and the rigging wire / terminals....as some dirt/corrosion can lead to noise generated and being picked up directly at / thru the antenna, and if that's the case, NO filtering/ferrites/wires/etc. will make any difference....so, just make sure the connections are clean/tight and secure...



The power cable runs straight to the battery.
I've got ferrites on the power cable, the antenna control cable (at the radio).
This is good....but, adding the "Line Isolator" is a very good idea!!


I've got a KISS that runs off the AH-4 and then aft under some cabinets on the edge of the hull, above the waterline. It's about a foot too long for the space, so the last foot or so bends up in a u-turn.
The KISS is not cause of your troubles, or it shouldn't be!
(although it is possible that the KISS is picking up some RF noise and directly conducting back to your AH-4/IC-7200....unlikely, but simply disconnecting it and seeing what happens is an easy test!)


If I turn everything off... and I mean everything but the radio and the notebook (not charging), I still get a lot of interference/noise/static. Even out in the boondocks with no cell coverage.
This is the sentence that made me wonder (and ask) if you are sure that you are actually hearing RFI / RF Noise, or are you hearing natural atmospheric noise???

And remember, that you MUST turn OFF any "pre-amp" and play with the RF Gain (turn it down), otherwise you are just amplifying and increasing your noise!!!!


I've been able to transmit emails via RMS Express, but not receive.

I reset my 7200 and that seemed to help. I'm starting to wonder if either RMS Express or the Chirp software I programmed my Icom with is scrambling something. When I reset the 7200 the waterfall display in RMS Express changed, and would show the impact of the various filters.
I understand the "attraction" of using digital comms...but remember we humans are analog, as is most of the RF noise....so, please take this as well intentioned advice...
Try the radio on Voice....and listen....and listen....and listen....

Also, be sure you look at the videos showing / describing various RF noises, in a live, real-world environment (on-board a 47' sloop, tied to a dock, in S. Florida), not in a special lab or professional environ....


Since I had a better way to gauge the signal quality I started tweaking several things, like the mic level and rf/sql. I was able to determine I needed more insulation from my notebook, so after adding 3 more ferrites to the usb cable (that had 2 built in on each end) I had a cleaner signal, but I still have RFI issues even when the notebook is off and disconnected.
This is the second sentence that made me wonder (and ask) if you are sure that you are actually hearing RFI / RF Noise, or are you hearing natural atmospheric noise???

But also, wondering if your computer could be excessively noisy (RF-wise)???



I've been able to have some success with voice, talking on the sonrisa net, but only with close strong signals. I have issues with weaker signals. Trying to talk to a buddy in San Carlos he was barely readable.
This is the third sentence that made me wonder (and ask) if you are sure that you are actually hearing RFI / RF Noise, or are you hearing natural atmospheric noise?? BUT...

But, this is the first sentence that makes me wonder if you have a thorough understanding of radiowave propagation and antenna system performance on various bands/freqs for various ranges...
(this is a reason that HF-DSC has grown in popularity...especially in Distress comms, as it doesn't require the operator to know much about radiowave propagation, etc....but, other normal HF comms, whether PACTOR, Winmor, Voice, etc.) does!!!)


Please read the info and watch the videos on choosing the correct band/channel/freq for your communications path and distance to cover....where we have some initial info on radiowave propagation, as well....


I've had better luck with RMS Express receiving emails since I added the ferrites to the PC, but it still has too much noise where sometimes I have to override the busy indicator (I can hear the channel is free) and then it connects.
Make sure you have the 7200's "pre-amp" OFF...and turn the RF Gain Down!



So here's my list of questions, for those of you who might be willing to help me some more:
1) I am going to order a T4 isolator and put that in the system, I've been using this as a reference http://sfbaysss.org/resource/doc/Mar...ferson2014.pdf


2) I am going to order a MFJ-874 from HRO (the wife is making a supply run to the USA for Christmas) -- will this help troubleshoot?
A power/swr meter is good to have....but, will be of no help to these problems....
I prefer the Diawa's....but there's no denying that some MFJ stuff is adequate...but...
But, a "dual-needle" meter is usually MUCH easier for those untrained/inexperience to use....and easier to "see what's going on, by just a glance"...


3) More ferrites
Always good to have....


4) I'm going to see if I can run the KISS differently, or possible add another wire and send it to the rudder or something?
No need to run the KISS differently.....if you think it's a problem, do a connected/disconnected test...


5) Is the stash of wires near the antenna cable running from the radio to the tuner a problem?
Probably not...

6) I'm not sure if I'm getting noise from the solar panels, even if I turn them off (killing the breakers on both sides of the MPPT)
Nothing to worry about here....it's the MPPT controller that would be generating the RFI....but, here you've got no worries....


7) I'm in a slip in La Paz right now, trying to get jvcomm32 to work with weatherfax, but too much noise there too. Will try again at night to see if it makes a difference.
See ALL info above!

8) It seems like the lower freqs I have more noise on than the higher freqs
Yes....that is what HF comms is all about!!!
Please read the info and watch the videos....and turn the 7200's pre-amp OFF....and turn the RF Gain down...


Any other tips or tricks I should try? I've been reading the regular and advanced manual for my radio, and gotten a little better with it, but I'm still having issues with RFI (I'm pretty sure)


Well, I think that's all for now....yeah, there is more to all of this....but, the above should get you started...

Fair winds...

John
__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Old 11-12-2015, 16:56   #5
Registered User

Join Date: May 2011
Location: Toronto
Boat: Sandpiper 565
Posts: 2,645
Re: Too much RX noise on HAM setup

Repeating for emphasis:

Quote:
Originally Posted by waterman46 View Post
You could try running a long wire, hoisted on a halyard, directly to the RF jack on your ICOM to eliminate any possibility of the tuner or antenna system causing a problem. I know these are very unlikely noise sources but at this point you need to get to the basics.
I don't yet have specific experience with SSB installs on boats, but I do have an electronic background and have been messing with shortwave receivers since forever.

Similar to above, I would try to take just the SSB radio physically off the boat (eg to a car), power the radio - ideally with a stand-alone battery, connect a wire of moderate length (10 ft?) as an antenna, and try receiving. If you're getting reception with far less noise, you know it's something on the boat. If you still have noise but you're nowhere near a potential noise source... it's the receive section of the radio.

Another test on the boat, similar to what Doug mentioned, is to get a portable shortwave receiver tuned to close to where the SSB radio is tuned, and see if you get similar noise levels in the portable radio. Move it around to see how the noise changes. It might lead you to the noise source.

For shortwave listening at home, I've found that alot of things throw out serious interference at shortwave HF frequencies. Computers are one; but by far the biggest noisemaker for me has been dimmers, and solid-state voltage converters (120v to 12v) for 12v halogen lighting.

Good luck.
__________________
Lake-Effect is offline   Reply With Quote
Old 11-12-2015, 17:05   #6
Registered User
 
MYTraveler's Avatar

Join Date: May 2010
Posts: 151
Re: Too much RX noise on HAM setup

Being new to Ham/SSB, it took me quite a while to determine that my setup was not performing properly and then to get it fixed, despite professional installation and the help of a bunch of different "experts". The first think you should do is try to tune into 5, 10 and 15 Mhz, on which time ticks are continuously broadcast with voice annunciation at the beginning of each minute. Depending on conditions, you can usually pick up one pretty clearly, although there is always (at least on my system, without squelch) some noise. If you can typically receive at least one of those clearly, the reception side is probably working fine. As for transmit, try WLO -- a commercial ship to shore radio telephone operator. They will give you a radio check for free and will do a good job of reporting the strength and quality of your signal.

If you have trouble making contact, try to get someone to measure the strength of your signal with a field strength meter.

The biggest problem with my installation turned out to be that the fitting on the end of the cable that connects my tuner to antenna was not properly sealed, with the result that the cable got corroded and became highly resistive. If found that one myself, almost by accident.
__________________
MYTraveler is offline   Reply With Quote
Old 11-12-2015, 17:39   #7
Registered User
 
autumnbreeze27's Avatar

Join Date: Apr 2012
Location: Cruising Mexico
Boat: 50' Herreshoff Ketch
Posts: 892
Re: Too much RX noise on HAM setup

Thanks all for the responses.

As for other cables, it's the nav table, so power various devices, vhf antenna, nmea, etc.

I recently re-terminated the GTO-15 to the shroud. It was corroded, I did a half-ass job when I first set it up, and it was all corroded. I was thinking about re-doing a 3rd time using the bulldog clamp method mentioned in the Michael Jefferson PDF.

I definitely need to read up on what freq/what time of day.

As for figuring out voice comms first, that's what lead me to a big leap in data comms. I was listening to sonrisa net out on the anchor at Espiritu Santo and plugged my notebook in, and noticed the static that came on the radio. After adding 3 additional ferrites to the USB cable the static was greatly reduced. I read online that keyboards and mice can cause static, so I had ferrites on them both. I would try disconnecting everything from my notebook (keyboard/mice/etc) to minimize noise, but never realized that morning I played with the it and my external keyboard and mouse were fine, it was the touchpad on the notebook that caused huge static!

So maybe it's atmospheric? I've removed the AH4 cabling and am going to remount it. I'd tell you how it was mounted before but you'd just make fun of me. Is it worth re-running the coax and control cables so they are isolated from everything else? That was my plan for tomorrow, but otherwise that would save me an hour or so.

Any tips on tuning the 7200 are welcome. When I greatly reduced the background noise with my ferrites I found I'd back the RF/SQL knob down to 10 o'clock or so, and that would put the sound signal below the green mark, but I'd get the channel clear indicator. I would usually crank it back up to 12 o'clock once the transmission started, is that not wise?

One thing that I find is odd is how RMS Express works. If you make a GRIB request, do you have to reconnect to the same station to get the response?

I was getting about 50% acks after tweaking things, and I sent 3 emails and got 1 response about 1 of the emails being routed to CMS, yet when I got to La Paz and connected via telnet I got many more messages from farther back.

Is that just an issue with my RX problems, or do the messages stack up on the last station you connect to?

When I was out on the hook in Espiritu Santo I was able to talk to a guy in Texas just fine. Not sure if that was 14300 or not. I haven't done any long range talking yet, I guess the next step is to point me in that direction?

I just checked my winlink to find out my buddy in San Carlos I was trying to talk to doesn't have a decent ground for his long wire. D'oh! Going to see if he can make a dipole or something.

Thanks all!
__________________
autumnbreeze27 is offline   Reply With Quote
Old 11-12-2015, 17:54   #8
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 1,886
Re: Too much RX noise on HAM setup

autumnbreeze,
Sorry don't have the time tonight, to go through all of this again....but, as I wrote earlier, all of the answers to your questions (whether RFI, freqs/channel choice, radio install procedures, etc.) are there in the links in the "sticky"...
Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, etc.)

And, if you watch the videos, you'll see live demonstrations in the real world...


One thing that I really need to point out....
There is no reason to believe that running coax (or tuner control cables) near other wiring is causing you any problems...
The radio signals travel on the inside of the coax, and if you have ferrites on the coax (and control cables) you've effectively eliminated any common-mode noise that may be traveling on the outside of things (and possibly being picked up by the radio)....

My best advice is to please spend you time learning what the problem is, not thinking that something is wrong with the radio or computer, etc...and especially not re-inventing the wheel...
AND...
And, in particular, when you learn how things work, you'll be learning how to use the radio (not reading the manual, but rather learning what each knob's feature actually DOES...)

(I'm still not sure you have much RFI anymore....so please turn the darn pre-amp OFF! and turn the RF Gain down...and read the sticky, read the links, watch the videos)


I hope this helps...

John
__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Old 11-12-2015, 18:15   #9
Registered User
 
Capt.Don's Avatar

Join Date: Aug 2010
Location: Altadena, CA
Boat: Tartan 3500
Posts: 530
Images: 1
Re: Too much RX noise on HAM setup

A lot of good info here. I have some minor RFI issues causing one of my USB-Serial adapters to lockup, interference with the autohelm and LEDs flickering. For me, these are repeatable on certain lower frequencies (e.g., less then 4Mhz).

A few more tips that I'm experimenting with (once we get the boat back from PV),

1) Be sure you are using #31 ferrites and not the ones you find on eBay or RadioShack. Buy the larger ones (center 3/8") and wrap the cord 3 or 4 times through the core. Their effectiveness multiples with the number of wraps. I also put the ferrites on both ends of all the cables to/from the radio, modem, and laptop. Once RFI is isolated, I may remove one at a time and see if needed.

2) When transmitting data, try a lower power.

3) RFI grounding (or lack) may be the source of the RFI.

4) Look for a better quality USB-Serial adapter. I had two: Keyspan and an inexpensive CH340. The Keyspan works great and my problems were always with the CH340 adapter. I've just purchased a GearMo USB-Serial adapter that uses FTDI driver. One observation, the Keyspan and the GearMo have the DB9 and USB shells connected (common ground) giving a good ground to the laptop. The CH340 did not ground the outer shells. I believe that my lack of ground on the CH340 adapter may be the cause of it locking up.

5) I too have the KISS-SSB as a ground. I've been told that the KISS-SSB introduces RFI; however, I'm discounting that claim until I've had a chance to replace the ferrites and use the new USB-Serial adapter. As John pointed out, it is easy enough to disconnect the KISS-SSB to see if that reduces the RFI.

I won't have a chance to experiment more with this till March/April; however, based on everything I've read, these are my next steps.

Good luck!
Don
__________________
Capt.Don is offline   Reply With Quote
Old 12-12-2015, 14:10   #10
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 1,886
Re: Too much RX noise on HAM setup

autumnbreeze,
Some here seemed to be missing that you report still having "noise" when your notebook is off and disconnected, as well as when "everything else" is off as well....
And, in remote anchorage, too...
SO...
So, no amount of ferrites will help you!

It's either:
a) natural, atmospheric noise....
b) poor channel choice, lack of understanding of radiowave propagation...
c) radio misadjusted...
BUT...
But, most likely all three!!!


---- Just to expand a bit on my earlier comments, please make sure the 7200's pre-amp is OFF!
Unless you are in a very RF quite area, and are on the higher HF bands, 21mhz and above, the pre-amp does NOTHING at all but add noise/distortions to the receiver....oh, it does allow you to "see" a higher signal registration on the "S-meter", but that doesn't mean it has improved anything...and usually it's making things worse....

---- Also, make sure that the Noise Blanker (NB) is OFF....or at least on its minimum setting!
Once they are adjusted high enough to actually remove some impulse noise, DSP noise blankers usually distort the signals enough to be impractical to use on SSB and cause significant distortions and increased bit-error rates in digital modes...

---- And, make sure you do not have any of its "PBT" features, nor "notch filters", selected....they should be OFF for digital modes, unless you have some specific interference from another station on-the-air or a fixed carrier somewhere...



---- Especially watch these videos....
"Choosing the Correct Channel / Freq / Band, for distance 'n time-of-day"



"Atmospheric Noise and Radio Signals"



"RFI, man made noise (on board and from shore, and/or other boats)"





Also be sure to watch these videos....
"Maritime HF Comms"
https://www.youtube.com/playlist?lis...ZDo_Jk3NB_Bt1y


"Offshore Weather"
https://www.youtube.com/playlist?lis...zdjTJjHlChruyY


"HF-DSC Comms"
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX




I hope this helps..


Fair winds...

John
__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Old 12-12-2015, 14:33   #11
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 1,886
Re: Too much RX noise on HAM setup

Don,
It's unfortunate that there is so much misinformation about RF grounds / antenna grounds out there....especially the KISS..

Make no mistake, I'm not a fan of the KISS....as it does not do what they say it does (it isn't a tuned / resonant system!), and the fact that you can make your own counterpoise that performs better for Free (or at most $5)....
Re: KISS-SSB Counterpoise

BUT...
But, it is very highly unlikely that any "ground system", whether the KISS, or any other, actually picks up RF noise and contributes to anyone's on-board receive RFI problems...(transmit RFI issues, YES....but not receive RFI)
(I would write that it's impossible....but, then someone would argue with me....and I've given up commenting about the KISS, other than what I write here, let alone get into arguments about it!)




As for your transmit RFI....well, it could just be antenna radiated (meaning if can't keep it out of the USB adapters / cables, there's nothing you can do about it)....
BUT...
But, it could be that if you actually had a direct sea water RF ground / antenna ground, you'd be able to get more of your RF current reradiated by the antenna (which is what the antenna ground's main purpose is!), or at least shunt much of the "stray RF" to "ground"....either way, chances are good this would eliminate your transmit RFI....
(of course adding a Line Isolator, first, is an easier test...and ALWAYS a good idea!!)


A few clarifications....
Quote:
Originally Posted by Capt.Don View Post
1) Be sure you are using #31 ferrites and not the ones you find on eBay or RadioShack. Buy the larger ones (center 3/8") and wrap the cord 3 or 4 times through the core. Their effectiveness multiples with the number of wraps.
Actually the electiveness goes up exponentially!!


I also put the ferrites on both ends of all the cables to/from the radio, modem, and laptop. Once RFI is isolated, I may remove one at a time and see if needed.


2) When transmitting data, try a lower power.
"autumnbreeze" was commenting on receive RFI....

3) RFI grounding (or lack) may be the source of the RFI.
"autumnbreeze" was commenting on receive RFI....and while grounding of the interfering systems can improve receive RFI, it is very unlikely that improving radio's RF / Antenna ground will make any difference for receive RFI (transmit RFI, yes....not receive RFI...)

4) Look for a better quality USB-Serial adapter. I had two: Keyspan and an inexpensive CH340. The Keyspan works great and my problems were always with the CH340 adapter. I've just purchased a GearMo USB-Serial adapter that uses FTDI driver. One observation, the Keyspan and the GearMo have the DB9 and USB shells connected (common ground) giving a good ground to the laptop. The CH340 did not ground the outer shells. I believe that my lack of ground on the CH340 adapter may be the cause of it locking up.


5) I too have the KISS-SSB as a ground. I've been told that the KISS-SSB introduces RFI; however, I'm discounting that claim until I've had a chance to replace the ferrites and use the new USB-Serial adapter. As John pointed out, it is easy enough to disconnect the KISS-SSB to see if that reduces the RFI.
See above and especially the link I posted above...for details..


I won't have a chance to experiment more with this till March/April; however, based on everything I've read, these are my next steps.

Good luck!
Don
Fair winds...

John
__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Old 12-12-2015, 15:25   #12
Registered User

Join Date: Feb 2011
Posts: 2,066
Re: Too much RX noise on HAM setup

Check your ground before spending all that money. You do have a ground, don't you? Ideally its a big lead plate at the bottom of your hull, independent of your other grounding plates for general purposes.
__________________
reed1v is offline   Reply With Quote
Old 12-12-2015, 15:27   #13
Registered User
 
autumnbreeze27's Avatar

Join Date: Apr 2012
Location: Cruising Mexico
Boat: 50' Herreshoff Ketch
Posts: 892
Re: Too much RX noise on HAM setup

Downloading some of the youtube videos now.

I just got my setup hooked back up. I didn't re-terminate the shroud connection yet, figured I'd play with it first.

I don't use the P.Amp except for weak signals using voice, but as you mentioned it usually amps the static as well, and unless I can filter it out I usually leave it off.

When using digital, I follow the RMS Express help file, which says to turn on Fast AGC, and I use the Middle filter set at 1800. I leave NB and NR off for data.

I relocated my tuner to a better spot, which allowed me to run my KISS flat and in straight line, no more u-turn. I added a ferrite to the tuner end of the controller cable. I added a ferrite to the USB cable on the radio side, so now on the radio side I have a built in ferrite + one with 4 wraps, and on the PC side I have a built in ferrite + 2 with 4 wraps. My radio has USB built in, so no adapter required.

I was able to pick up the time ticking on 10000, 15000, and 20000. I tried some weatherfax but didn't have any luck there. I figure I should watch the videos first before asking any more questions about it.

I've been going through the manual and am getting pretty good at what all the knobs do, but one thing I haven't found much info on is how exactly to use the filters. I basically use trial and error and found the narrow filter works pretty good at the default rate for voice, but I'm just taking stabs at it.
__________________
autumnbreeze27 is offline   Reply With Quote
Old 12-12-2015, 15:46   #14
Registered User
 
Capt.Don's Avatar

Join Date: Aug 2010
Location: Altadena, CA
Boat: Tartan 3500
Posts: 530
Images: 1
Re: Too much RX noise on HAM setup

John - Thanks for the clarification! I knew the pros/cons re: KISS-SSB before installing. There's a lot of good information about proper ground and KISS on this forum. For me, it was easy to install and works well enough. I think my RFI issue(s) are manageable with proper ferrites and USB-Serial adapters.

Thank you for responding in detail to all these SSB installation issues
Don
__________________
Capt.Don is offline   Reply With Quote
Old 12-12-2015, 20:25   #15
Senior Cruiser
 
Ann T. Cate's Avatar

Join Date: Nov 2011
Location: aboard, cruising in Australia
Boat: Sayer 46' Solent rig sloop
Posts: 7,353
Re: Too much RX noise on HAM setup

Autumnbreeze,

You're in a marina and you're trying to fix up your radio reception? If this is so, be aware that we usually receive a lot of RF noise when in marinas, often so much that you can't copy anything but nearby stations.

If you have your noise problem when you're well out to sea, and there's no solar flare or such, then you likely do have a problem.

Not being able to talk from La Paz on 40 m. to San Carlos, would be a distance/time of day sort of problem, unless guys out at anchor can do it okay.

For your sake, I'm hoping it is just horrid marina noise, and not a horrid radio problem.

Cheers, mate,

Ann
__________________

__________________
Ann & Jim, U.S. s/v Insatiable II, free at last, will check in when in internet range
Ann T. Cate is offline   Reply With Quote
Reply

Tags
noise

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
380: 380 Reefing setup - too much friction Zoid Lagoon Catamarans 10 06-05-2015 01:08
How Much Is too Much ? santana 22 Seamanship & Boat Handling 10 07-05-2010 08:38
How Much Is Too Much? SVMorningStar Construction, Maintenance & Refit 11 04-02-2010 10:30
How much boat is too much? David M General Sailing Forum 36 09-10-2007 20:02
Draft depth for Caribean Islands - how much is too much? theloneoux General Sailing Forum 11 07-08-2005 14:21


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 07:18.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.