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Can you really dry out a Xmtr?
- Thread starter oldnewbie
- Start date
M
MattB
Guest
> Watching what is happening in the New Orleans area, I can't
> help but wonder...
>
> If a transmitter gets flooded, is it ever gonna be usable
> again? Can you really dry it out and re-use it? Or is all
> that stuff just so much junk?
>
You can dry anything out, the main problem is, if the TX was powered up while the water got in it, most of the components will be toast.<P ID="signature">______________
</P>
> help but wonder...
>
> If a transmitter gets flooded, is it ever gonna be usable
> again? Can you really dry it out and re-use it? Or is all
> that stuff just so much junk?
>
You can dry anything out, the main problem is, if the TX was powered up while the water got in it, most of the components will be toast.<P ID="signature">______________
</P>
L
Les
Guest
> If a transmitter gets flooded, is it ever gonna be usable
> again? Can you really dry it out and re-use it? Or is all
> that stuff just so much junk?
Usable....
Maybe for a short time.
If the transmitter was already off due to power failure when
the water got in you're a little bit ahead of the game.
But flood water is NOT pure. Even if it were drowned in distilled water
there would still be some bits and pieces that wouldn't dry completely
and ready to bite you the minute you fired it up.
But, worse, all the contaminents in the water (not to mention the
probable salt) will sit there quietly eating away at stuff.
You might be able to get a transmitter dry enough and clean enough
to work for a short time...perhaps months...but you could never
rely on it. Still, if you're gonna be a while in getting a
replacement, couldn't hurt to try so long as all the interlocks are
in place, working, and you stand well back when you hit it with
power.
But don't forget the load! Make sure you don't have transmission
line full of water and that all antenna related connections are clean
and tight (primarily AM).
After all, I've washed old equiment in hot soapy tap water to get mouse
dung out of it and still gotten a little more life out of it. But
never an entire transmitter!
<P ID="signature">______________
I once took something seriously.
And was accused of shoplifting.</P>
> again? Can you really dry it out and re-use it? Or is all
> that stuff just so much junk?
Usable....
Maybe for a short time.
If the transmitter was already off due to power failure when
the water got in you're a little bit ahead of the game.
But flood water is NOT pure. Even if it were drowned in distilled water
there would still be some bits and pieces that wouldn't dry completely
and ready to bite you the minute you fired it up.
But, worse, all the contaminents in the water (not to mention the
probable salt) will sit there quietly eating away at stuff.
You might be able to get a transmitter dry enough and clean enough
to work for a short time...perhaps months...but you could never
rely on it. Still, if you're gonna be a while in getting a
replacement, couldn't hurt to try so long as all the interlocks are
in place, working, and you stand well back when you hit it with
power.
But don't forget the load! Make sure you don't have transmission
line full of water and that all antenna related connections are clean
and tight (primarily AM).
After all, I've washed old equiment in hot soapy tap water to get mouse
dung out of it and still gotten a little more life out of it. But
never an entire transmitter!
<P ID="signature">______________
I once took something seriously.
And was accused of shoplifting.</P>
S
SamBuca
Guest
> You can dry anything out, the main problem is, if the TX was
> powered up while the water got in it, most of the components
> will be toast.
Even if it were off I'm sure some capacitors would still be holding a charge to cause a short.<P ID="signature">______________
</P>
> powered up while the water got in it, most of the components
> will be toast.
Even if it were off I'm sure some capacitors would still be holding a charge to cause a short.<P ID="signature">______________
</P>
T
TXengineer
Guest
A TV Station which will remain nameless (NOT one that I work for, for those who know me), was having the roof worked on, in their transmitter building. One night a heavy rain broke through the tarp on the roof, dowsing the transmitter that was ON the air. The transmitter was only five years old at the time. Never had a minute of off air time in that first five years due to transmitter failure. However after the water, that was 20 years ago. They have had NOTHING but issues with it since then. Too bad their owners didn't think it was worth replacing 10 years ago...
W
wannabenewsboy
Guest
> If a transmitter gets flooded, is it ever gonna be usable
> again? Can you really dry it out and re-use it? Or is all
> that stuff just so much junk?
Further down the line on this board (I think) when some of us were sharing "roast" stories, someone talked about an old Collins unit that he dried out and was able to use after it had gotten wet from water used to put out the fire at the transmitter building. I'm sure there would be a lot of parts that would have to be flat out replaced due to corrosion, and I don't know how much of it would be usable or for how long (I'm not an engineer, I just pretend I am sometimes), but depending on the unit, there is a chance you will get some more life out of it.<P ID="signature">______________
</P>
> again? Can you really dry it out and re-use it? Or is all
> that stuff just so much junk?
Further down the line on this board (I think) when some of us were sharing "roast" stories, someone talked about an old Collins unit that he dried out and was able to use after it had gotten wet from water used to put out the fire at the transmitter building. I'm sure there would be a lot of parts that would have to be flat out replaced due to corrosion, and I don't know how much of it would be usable or for how long (I'm not an engineer, I just pretend I am sometimes), but depending on the unit, there is a chance you will get some more life out of it.<P ID="signature">______________
> A TV Station which will remain nameless (NOT one that I work
> for, for those who know me), was having the roof worked on,
> in their transmitter building. One night a heavy rain broke
> through the tarp on the roof, dowsing the transmitter that
> was ON the air. The transmitter was only five years old at
> the time. Never had a minute of off air time in that first
> five years due to transmitter failure. However after the
> water, that was 20 years ago. They have had NOTHING but
> issues with it since then. Too bad their owners didn't think
> it was worth replacing 10 years ago...
I think Les's comment about contaminants in the water is probably the ongoing cause of the problems. Even distilled water would suddenly become contaminated with conductive solutes from the equipment itself, which would remain on the exterior of every component, and will attract even more airborne contaminants over time. This will cause some components to operate outside tolerance. Contaminated equipment will be affected far more dramatically by slight changes in humidity, too.
Another factor is corrosion in and around any types of contacts and connectors, for which the corrosive process continues indefinitely, as long as any chemically-reactive contaminants remain. Think of what can happen if just one tenth of an ohm of resistance suddenly develops across a ground connector in an enclosure for an IOT. The best case scenario is that the connector welds itself closed.
Treat the equipment similarly as a restoration project for a vintage radio that was in a basement for 50+ years. Take apart and clean all contacts until they shine. Replace transformers (which can hold water and contaminants indefinitely), regardless of how well they seem to perform. I made the mistake of not doing this once; it's not nice when a bundle of turns in the primary suddenly become shunted! All remaining circuitry should be cleaned with a chemical contact cleaner to remove any residue. Anything water-based will leave behind contaminants.
Last, management simply has to accept the fact that during the process, it may become reality that the equipment is simply too far gone to salvage. They have already been attending the same history class for 20 years.
> for, for those who know me), was having the roof worked on,
> in their transmitter building. One night a heavy rain broke
> through the tarp on the roof, dowsing the transmitter that
> was ON the air. The transmitter was only five years old at
> the time. Never had a minute of off air time in that first
> five years due to transmitter failure. However after the
> water, that was 20 years ago. They have had NOTHING but
> issues with it since then. Too bad their owners didn't think
> it was worth replacing 10 years ago...
I think Les's comment about contaminants in the water is probably the ongoing cause of the problems. Even distilled water would suddenly become contaminated with conductive solutes from the equipment itself, which would remain on the exterior of every component, and will attract even more airborne contaminants over time. This will cause some components to operate outside tolerance. Contaminated equipment will be affected far more dramatically by slight changes in humidity, too.
Another factor is corrosion in and around any types of contacts and connectors, for which the corrosive process continues indefinitely, as long as any chemically-reactive contaminants remain. Think of what can happen if just one tenth of an ohm of resistance suddenly develops across a ground connector in an enclosure for an IOT. The best case scenario is that the connector welds itself closed.
Treat the equipment similarly as a restoration project for a vintage radio that was in a basement for 50+ years. Take apart and clean all contacts until they shine. Replace transformers (which can hold water and contaminants indefinitely), regardless of how well they seem to perform. I made the mistake of not doing this once; it's not nice when a bundle of turns in the primary suddenly become shunted! All remaining circuitry should be cleaned with a chemical contact cleaner to remove any residue. Anything water-based will leave behind contaminants.
Last, management simply has to accept the fact that during the process, it may become reality that the equipment is simply too far gone to salvage. They have already been attending the same history class for 20 years.
> > You can dry anything out
KQNG in Lihue, Kaua'i is replacing their original, mid-1980's vintage CCA 20KW transmitter later this month. In September of 1992, Hurricane Iniki ripped the roof off of the transmitter building, and the transmitter took about 20 inches of rain directly into everything.
New plate transformer, new choke, and a new filament transformer brought it back to life. But it has never been the same.
And now, 13 years later, we are finally throwing it away. It has mostly failed mechanically at this point, but it is a miracle that it is still working at all.
But that's what engineers are good for, of course.
KQNG in Lihue, Kaua'i is replacing their original, mid-1980's vintage CCA 20KW transmitter later this month. In September of 1992, Hurricane Iniki ripped the roof off of the transmitter building, and the transmitter took about 20 inches of rain directly into everything.
New plate transformer, new choke, and a new filament transformer brought it back to life. But it has never been the same.
And now, 13 years later, we are finally throwing it away. It has mostly failed mechanically at this point, but it is a miracle that it is still working at all.
But that's what engineers are good for, of course.
> > If a transmitter gets flooded, is it ever gonna be usable
> > again? Can you really dry it out and re-use it? Or is
> all
> > that stuff just so much junk?
>
> Further down the line on this board (I think) when some of
> us were sharing "roast" stories, someone talked about an old
> Collins unit that he dried out and was able to use after it
> had gotten wet from water used to put out the fire at the
> transmitter building. I'm sure there would be a lot of
> parts that would have to be flat out replaced due to
> corrosion, and I don't know how much of it would be usable
> or for how long (I'm not an engineer, I just pretend I am
> sometimes), but depending on the unit, there is a chance you
> will get some more life out of it.
>
I dried out a Collins 20V2 am about 12 years ago. Only the lower half was flooded. Best I remember I pulled the plate transformer, dried it the best i could with hot air then connected 2 1500 watt electric heaters in parallel and then connected them in series with the primary, put a short on the secondary, plugged it up and let it cook. The heaters and the current through the primary heated the transformer and in about 24 hours I got brave enough to connect a variac to the transformer, remove the short i placed on the secondary and slowly raise the primary voltage. To my supprise it worked and the transmitter was used for about 5 years before being retired to a backup. I baked the filter choke in the oven for a day. Man did that ever "P" the wife off! Never again.
> > again? Can you really dry it out and re-use it? Or is
> all
> > that stuff just so much junk?
>
> Further down the line on this board (I think) when some of
> us were sharing "roast" stories, someone talked about an old
> Collins unit that he dried out and was able to use after it
> had gotten wet from water used to put out the fire at the
> transmitter building. I'm sure there would be a lot of
> parts that would have to be flat out replaced due to
> corrosion, and I don't know how much of it would be usable
> or for how long (I'm not an engineer, I just pretend I am
> sometimes), but depending on the unit, there is a chance you
> will get some more life out of it.
>
I dried out a Collins 20V2 am about 12 years ago. Only the lower half was flooded. Best I remember I pulled the plate transformer, dried it the best i could with hot air then connected 2 1500 watt electric heaters in parallel and then connected them in series with the primary, put a short on the secondary, plugged it up and let it cook. The heaters and the current through the primary heated the transformer and in about 24 hours I got brave enough to connect a variac to the transformer, remove the short i placed on the secondary and slowly raise the primary voltage. To my supprise it worked and the transmitter was used for about 5 years before being retired to a backup. I baked the filter choke in the oven for a day. Man did that ever "P" the wife off! Never again.
> > > You can dry anything out
<snipped>
Had that problem at a site, we lost a McMartin and a Harris...Both 5KW boxes. Shotgunned the power supplies and replaced any HV wireing. Still working to this day in 24-7 service. BTW this happened 15 years ago. It really depends on the damage and as others have mentioned the conditions. I was lucky, this was a 100 year flood and about 2 feet of water for about 2 days. Lots of cleaning...did I say lots of cleaning? Really dont want to do it again if I don't have to. Perhaps we were lucky.
Lane
<snipped>
Had that problem at a site, we lost a McMartin and a Harris...Both 5KW boxes. Shotgunned the power supplies and replaced any HV wireing. Still working to this day in 24-7 service. BTW this happened 15 years ago. It really depends on the damage and as others have mentioned the conditions. I was lucky, this was a 100 year flood and about 2 feet of water for about 2 days. Lots of cleaning...did I say lots of cleaning? Really dont want to do it again if I don't have to. Perhaps we were lucky.
Lane
> A TV Station which will remain nameless (NOT one that I work
> for, for those who know me), was having the roof worked on,
> in their transmitter building. One night a heavy rain broke
> through the tarp on the roof, dowsing the transmitter that
> was ON the air.
Similar situation:
Workers on the tower about 500 feet above the transmitter building dropped heavy tools on the roof of said building. They did not reveal their mistake (obviously).
At some point thereafter, heavy rains hit the area, and the roof broke open allowing water to pour directly over a Harris transmitter that was in operation at the time. I’m not sure the extent of damages.
This was at least three years ago, maybe even four or five. Said transmitter was repaired and is still in use today.
The situation in NO may or may not be as fortunate, especially if transmitters sit in flooded water for days/weeks/months.
> for, for those who know me), was having the roof worked on,
> in their transmitter building. One night a heavy rain broke
> through the tarp on the roof, dowsing the transmitter that
> was ON the air.
Similar situation:
Workers on the tower about 500 feet above the transmitter building dropped heavy tools on the roof of said building. They did not reveal their mistake (obviously).
At some point thereafter, heavy rains hit the area, and the roof broke open allowing water to pour directly over a Harris transmitter that was in operation at the time. I’m not sure the extent of damages.
This was at least three years ago, maybe even four or five. Said transmitter was repaired and is still in use today.
The situation in NO may or may not be as fortunate, especially if transmitters sit in flooded water for days/weeks/months.
> > > > You can dry anything out
>
>
> Had that problem at a site, we lost a McMartin and a
> Harris...Both 5KW boxes. Shotgunned the power supplies and
> replaced any HV wireing. Still working to this day in 24-7
> service. BTW this happened 15 years ago. It really depends
> on the damage and as others have mentioned the conditions. I
> was lucky, this was a 100 year flood and about 2 feet of
> water for about 2 days. Lots of cleaning...did I say lots of
> cleaning? Really dont want to do it again if I don't have
> to. Perhaps we were lucky.
>
> Lane
>
Lots of UHF TV rigs get wet because they are cooled with distilled water or a 50/50 mix of Glycol. The seals, hoses etc can and do break. The water needs to be out of it quickly or it starts to ruin even those parts that weren't in the water. Newer rigs with hermetically sealed relays have fewer problems but transformers are usually an issue. Plan on replacing anything below the water line and clean everything else. Just like a dry rig. If it's dirty you might get an arc. I would be confident the rig could run again as long as the components are available. If you have a Harris and have all of those exposed circuit boards all over the place than your in for a rough ride.
G
>
>
> Had that problem at a site, we lost a McMartin and a
> Harris...Both 5KW boxes. Shotgunned the power supplies and
> replaced any HV wireing. Still working to this day in 24-7
> service. BTW this happened 15 years ago. It really depends
> on the damage and as others have mentioned the conditions. I
> was lucky, this was a 100 year flood and about 2 feet of
> water for about 2 days. Lots of cleaning...did I say lots of
> cleaning? Really dont want to do it again if I don't have
> to. Perhaps we were lucky.
>
> Lane
>
Lots of UHF TV rigs get wet because they are cooled with distilled water or a 50/50 mix of Glycol. The seals, hoses etc can and do break. The water needs to be out of it quickly or it starts to ruin even those parts that weren't in the water. Newer rigs with hermetically sealed relays have fewer problems but transformers are usually an issue. Plan on replacing anything below the water line and clean everything else. Just like a dry rig. If it's dirty you might get an arc. I would be confident the rig could run again as long as the components are available. If you have a Harris and have all of those exposed circuit boards all over the place than your in for a rough ride.
G
If memory serves me correct, some of the New Orleans signals are built with the transmitters a few feet above the floor for the occasional fllods the area encounters with one in the area the storm hit (KKND in Delacroix,La.) at a reported 12 feet above HAAT due to flooding that sometimes occurs in the area (However I've heard the transmitter building of this station took a 12 foot log through it destroying it however)
RFLA
RFLA
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