I think you are referring to a dummy load. That plus an SWR meter will tell you little
other than power output. What you want to find is someone with an antenna analyzer, not an inexpensive or common tool but one most hams have.
Question for Radio Heads
- Thread starter Roger Long
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other than power output. What you want to find is someone with an antenna analyzer, not an inexpensive or common tool but one most hams have.
I had a similar situation as you describe. When approaching a marina the dockmaster later told me all he was getting on his handheld was gibberish. I tried the radio at the dock hailing a boat 20 ft away and he heard me fine. Reception was OK but I was not getting out in any clear audible manner to any distance. A quick trip up the mast discovered the connector to the antenna had become separated. Probably the dam fat osprey that had been eating fish of the top of the mast.
Roger,
I call ham radio nets occasionally and get people "checking in" with similar issues. It's almost always a microphone wiring problem or low voltage usually from handhelds with dead batteries. Since yours isn't a handheld, check the power connections and the mic plug. Try wiggling (hi tech radio-speak) the mic cord at the entry to the transceiver and at the base of the mic, or any other stress points, as you are transmitting. Mismatched and poor antenna connections don't typically cause distorted audio to nearby receivers. When checking the voltage to the radio, be sure to measure when you key it up. You could have a corroded butt splice in the line that passes 12v with no load, but when you apply the load of the transmitter, it may be dropping. If you check your antenna connection, be sure to weatherseal it afterwards. A lot of people think coax connectors are weatherproof, but they aren't. A good wrap in butyl tape followed by electrical tape will protect it for years. Good Luck.
I call ham radio nets occasionally and get people "checking in" with similar issues. It's almost always a microphone wiring problem or low voltage usually from handhelds with dead batteries. Since yours isn't a handheld, check the power connections and the mic plug. Try wiggling (hi tech radio-speak) the mic cord at the entry to the transceiver and at the base of the mic, or any other stress points, as you are transmitting. Mismatched and poor antenna connections don't typically cause distorted audio to nearby receivers. When checking the voltage to the radio, be sure to measure when you key it up. You could have a corroded butt splice in the line that passes 12v with no load, but when you apply the load of the transmitter, it may be dropping. If you check your antenna connection, be sure to weatherseal it afterwards. A lot of people think coax connectors are weatherproof, but they aren't. A good wrap in butyl tape followed by electrical tape will protect it for years. Good Luck.
I love you guys. And I don't even have a VHF problem. But am about tomove my VHF antenna from cockpit coming to mast top. I hope I don't have to ask questions, but it is a comfort to know the answers are right here. Later when I put the 857d onboard..... Yup, I'll need some advice.
Same as in an aircraft, always have a handheld for backup, it bypasses a lot of problems.
Check it daily just in case.
Check it daily just in case.
Roger,
From you descripiton, i wouldn't think it was an antenna problem. First thought is low voltage when you key the transmit, and the current goes up. Second thought is mike trouble, most likely a bad connection of the shielding braid in the mike cord.
The first thing I'd do is replace the in line fuse and clean the fuse holder. The fuse holders usually are not sealed well and will develop corrosion causing the resistaince to increase causing voltage drop as the current increases.
Garbling of an FM transmitt signal is rarely caused by an antenna system problem at the power levels of marine VHF radios, strength swings yes but garbling no.
I guess I can qualify as a Radio Head, Amateur K3VKY 55 years, First Class Radio Telegraph 50 years, ran a two way repair shop 12 years, and 30 years as a Signal Integrity Engineer, still working at 74.
Fred Villiard
From you descripiton, i wouldn't think it was an antenna problem. First thought is low voltage when you key the transmit, and the current goes up. Second thought is mike trouble, most likely a bad connection of the shielding braid in the mike cord.
The first thing I'd do is replace the in line fuse and clean the fuse holder. The fuse holders usually are not sealed well and will develop corrosion causing the resistaince to increase causing voltage drop as the current increases.
Garbling of an FM transmitt signal is rarely caused by an antenna system problem at the power levels of marine VHF radios, strength swings yes but garbling no.
I guess I can qualify as a Radio Head, Amateur K3VKY 55 years, First Class Radio Telegraph 50 years, ran a two way repair shop 12 years, and 30 years as a Signal Integrity Engineer, still working at 74.
Fred Villiard
Very interesting. When the radio wasn't working all, I watched my battery monitor while transmitting. The amp draw of the system as a whole went up about 5 amps.
Just now, when the radio is working again, the amp draw is about 4. It's a little hard to be precise because the exact reading doesn't remain steady on the digital display.
The way VHF works is that there is what is known as the "Capture Effect". This means that a stronger signal will capture the receiver completely and prevent it from receiving anything of any weaker signals being transmitted at the same time.
This means it can never make the "Fizzsseesheriznishbizseeeshooshfizshish" sound as a result of poor antenna or connections.
You are spelling it wrong anyway!
Similarly, and assuming the squelch has not been set to zero, if the signal is too weak or there are poor antenna or bad cable connections etc, the result is normally total silence.
You said you are not transmitting correctly but in fact you appear to be transmitting okay because others report clear signals from you. What is not happening is that your receiver is in trouble and making a mess of interpreting incoming signals.
It is possible that something on board is interfering with the set's internal detection and audio amplification circuitry. Anything else running intermittently that could cause this? This mush is possibly being imported on the DC power lines. Suspect your fridge, charger, alternator regulator, static inverter, TV, TV signal amp, even some makes of LED cabin and navigation lights. Try turning on and off one at a time whilst listening to an incoming VHF message - e.g. the weather.
BTW, as the set is permanently on, little indication will be seen from measuring the input current of the VHF set. It always increases when you operate the PPT switch anyway because of the extra 25 watts put out.
If none of the above I would then suspect dodgy loudspeaker connections or poor contact or tiny amounts of corrosion where the printed circuit board plugs in inside the set's case.
Open it, look at every plug connection and wiggle them. If the problem goes away you will have a working VHF for now but won't have solved anything!
Always remember the VHF radio is your first line coms system when things go wrong.
This means it can never make the "Fizzsseesheriznishbizseeeshooshfizshish" sound as a result of poor antenna or connections.
You are spelling it wrong anyway!
Similarly, and assuming the squelch has not been set to zero, if the signal is too weak or there are poor antenna or bad cable connections etc, the result is normally total silence.
You said you are not transmitting correctly but in fact you appear to be transmitting okay because others report clear signals from you. What is not happening is that your receiver is in trouble and making a mess of interpreting incoming signals.
It is possible that something on board is interfering with the set's internal detection and audio amplification circuitry. Anything else running intermittently that could cause this? This mush is possibly being imported on the DC power lines. Suspect your fridge, charger, alternator regulator, static inverter, TV, TV signal amp, even some makes of LED cabin and navigation lights. Try turning on and off one at a time whilst listening to an incoming VHF message - e.g. the weather.
BTW, as the set is permanently on, little indication will be seen from measuring the input current of the VHF set. It always increases when you operate the PPT switch anyway because of the extra 25 watts put out.
If none of the above I would then suspect dodgy loudspeaker connections or poor contact or tiny amounts of corrosion where the printed circuit board plugs in inside the set's case.
Open it, look at every plug connection and wiggle them. If the problem goes away you will have a working VHF for now but won't have solved anything!
Always remember the VHF radio is your first line coms system when things go wrong.
At the time I could hear the other vessel quite well. We have automated radio check stations here that play back a recording of your transmission along with an ad. I could hear the station ID and recorded AD perfectly but my recorded transmission sounded like mush.
I've cleaned up the connections I could reach and it seems to be working fine now.
Roger:
If you are heading towards Mystic I might suggest Dockside Electronics. Hev not used them for radio, and they have changed genrations over the past few years, but they have been great tech heads, very accommodating and can actually do repairs.
http://www.dockside-electronics.com/index.html
See you were up in my country on the Ct River, it is surprisingly beautiful.
Travel well.
If you are heading towards Mystic I might suggest Dockside Electronics. Hev not used them for radio, and they have changed genrations over the past few years, but they have been great tech heads, very accommodating and can actually do repairs.
http://www.dockside-electronics.com/index.html
See you were up in my country on the Ct River, it is surprisingly beautiful.
Travel well.
Bob Mack beat me to it. Dockside Electronics is not all that far of a walk from where your anchored. I haven't used them but also heard good things about them.
Im bummed I missed you by one day. Looks like you stopped at Noank Shipyard on the way up the river. That's my home marina. Been there for 8 years and love it. I was down kiking around on Sunday and it would have been great to hook up.
Please let me know the outcome of your radio issue. I'm fighting almost the same issue now.
Rob
Im bummed I missed you by one day. Looks like you stopped at Noank Shipyard on the way up the river. That's my home marina. Been there for 8 years and love it. I was down kiking around on Sunday and it would have been great to hook up.
Please let me know the outcome of your radio issue. I'm fighting almost the same issue now.
Rob
Oh yeah Roger I forgot to ask. Which Seatow automated were you using? CH24 in Old Saybrook or CH27 in Groton (really in Noank at Noank Shipyard)?
Hey Bob have you tried CH27 Seatow automated in Noank this spring? I haven't gotten a response at all with my ships radio and my handheld.
Hey Bob have you tried CH27 Seatow automated in Noank this spring? I haven't gotten a response at all with my ships radio and my handheld.
Darn. I just read this after running down to Stonington under power in fog that would do Maine proud.
The problem isn't moisture at the masthead. We had lots of rain overnight and, in thick fog, I can get an understandable record back from the mouth of the Connecticut River and a very clear one from Noak.
I guess there wouldn't have been any point in taking the radio in anyway.
The only significant difference I can think of between when the radio wasn't working and now is that we were sailing hard at 20-25 degrees of heel (Strider is an old fashioned gal and goes best that way.At this point, I would not rule out extraterrestrial interference:
I wish I had thought to roll up the jib and round up to minimal heel and try again on the radio.
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