Re: [Elecraft] To ground or not to ground
Normal practice is to connect the "ground" to the station ground buss. The station ground buss may be connected to a ground system at the base of the tower or somewhere near the station, provided it is ALSO tied directly to the AC mains ground for the structure. The point is to be certain there is but ONE mains ground for the structure and the station **without** relying on connections from the coax cables to the chassis to the mains outlet ground. Also, external devices normally have a seamless enclosure with only one side that opens for access to internal components. Normally it must be mounted with the side that opens facing downward, so rain will not get inside. Sealing such an enclosure is also possible, if you insist, but be sure to provide plenty of desiccant inside to absorb the moisture that will condense out of the air trapped inside unless you have an opening in the side facing downward. Otherwise you'll see a huge amount of corrosion in spite of sealing it against salt air. I would recommend calking only any seams that are facing to the sides or upward. Also, it is very important to provide "drip loops" on all cables entering the enclosure. Good designs have the connectors and any cable openings facing down since they are not 100% water tight. Drip loops will form naturally for any conductors coming from above. Be sure to run conductors coming from below to a point above the unit, then loop back down to form a drip loop. You guys in the warm climates really have it tough. Here on the Oregon coast I'm a few hundred yards from the surf, close enough that it's a constant background sound, and several times each winter we experience Cat 1 or 2 hurricane force winds blowing in off of the ocean, yet I have yet to experience salt corrosion on anything. Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Clint Sent: Saturday, February 18, 2012 2:51 PM To: elecraft@mailman.qth.net Subject: [Elecraft] To ground or not to ground OK, this is OT, sort of. It will be connected to my K3 so.. I just bought a remote mast mounted antenna switch (Ameritron RSC-8V). It comes with the center conductor electrically floating when the port is OFF. It seems to me I would be better off (safer) if the center conductor was grounded (or had a gas discharge tube or choke or resistor or??? when OFF. What do ya think? One thing is for darn sure, I am going to paint the cruddy polystyrene box and steel brackets (with "Rust Bullet" FYI), clean off the flux and coat the PC board before it sees the costal weather! Caulking will be in order also. Salty rain and spray are nasty even 5 miles in. 73, Clint KI6SSN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] To ground or not to ground
Clint, Not OT at all. Many remote antenna switches do it "the easy way", and use SPST relays to switch in the selected antenna - there is no way with that type relay to ground the antennas that are not currently selected. So yes, some type of static discharge device would be beneficial across each antenna connector to bleed off static. Usually a 100 uHy choke (of sufficient current capacity for your power level) or a 2 or 3 watt carbon resistor in the range of 3000 to 30,000 ohms will provide the DC path to bleed off any static charge. Imagine your antenna with a static charge - then you select that antenna - suddenly your transceiver is subjected to whatever charge was on the antenna. Sometimes OK, but other times, not so good. 73, Don W3FPR On 2/18/2012 5:51 PM, Clint wrote: > OK, this is OT, sort of. It will be connected to my K3 so.. > > I just bought a remote mast mounted antenna switch (Ameritron RSC-8V). It > comes with the center conductor electrically floating when the port is OFF. > It seems to me I would be better off (safer) if the center conductor was > grounded (or had a gas discharge tube or choke or resistor or??? when OFF. > > What do ya think? > > One thing is for darn sure, I am going to paint the cruddy polystyrene box > and steel brackets (with "Rust Bullet" FYI), clean off the flux and coat the > PC board before it sees the costal weather! Caulking will be in order also. > Salty rain and spray are nasty even 5 miles in. > > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] To ground or not to ground
On 2/18/2012 3:15 PM, Ron D'Eau Claire wrote: > You guys in the warm climates really have it tough. Here on the Oregon coast > I'm a few hundred yards from the surf, close enough that it's a constant > background sound, and several times each winter we experience Cat 1 or 2 > hurricane force winds blowing in off of the ocean, yet I have yet to > experience salt corrosion on anything. Of course not, Ron! It's so cold there, the NaCl is already crystallized out by the time it gets to your antenna. By that time, it's practically distilled water, probably blowing horizontally. :-) 73, Fred K6DGW Auburn CA CM98lw __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] To ground or not to ground
If you want to see a remote antenna switch that grounds all un-selected antennas, take a look at http://www.qsl.net/ei7ba/remote.htm It is quite easy to homebrew your own remote antenna switch. 73, Don W3FPR On 2/18/2012 6:26 PM, Don Wilhelm wrote: > Clint, > > Not OT at all. Many remote antenna switches do it "the easy way", and > use SPST relays to switch in the selected antenna - there is no way with > that type relay to ground the antennas that are not currently selected. > > So yes, some type of static discharge device would be beneficial across > each antenna connector to bleed off static. Usually a 100 uHy choke (of > sufficient current capacity for your power level) or a 2 or 3 watt > carbon resistor in the range of 3000 to 30,000 ohms will provide the DC > path to bleed off any static charge. > > Imagine your antenna with a static charge - then you select that antenna > - suddenly your transceiver is subjected to whatever charge was on the > antenna. Sometimes OK, but other times, not so good. > > 73, > Don W3FPR > > On 2/18/2012 5:51 PM, Clint wrote: >> OK, this is OT, sort of. It will be connected to my K3 so.. >> >> I just bought a remote mast mounted antenna switch (Ameritron RSC-8V). It >> comes with the center conductor electrically floating when the port is OFF. >> It seems to me I would be better off (safer) if the center conductor was >> grounded (or had a gas discharge tube or choke or resistor or??? when OFF. >> >> What do ya think? >> >> One thing is for darn sure, I am going to paint the cruddy polystyrene box >> and steel brackets (with "Rust Bullet" FYI), clean off the flux and coat >> the PC board before it sees the costal weather! Caulking will be in order >> also. Salty rain and spray are nasty even 5 miles in. >> >> > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] To ground or not to ground
On 2/18/2012 3:15 PM, Ron D'Eau Claire wrote: > You guys in the warm climates really have it tough. Here on the Oregon coast > I'm a few hundred yards from the surf, close enough that it's a constant > background sound, and several times each winter we experience Cat 1 or 2 > hurricane force winds blowing in off of the ocean, yet I have yet to > experience salt corrosion on anything. I formerly lived about 3 miles inland off the California coast (Pacifica, San Francisco area) where the fog came in almost every day and the salt would build up in the "eye" of the dipole insulators. --- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 >From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] To ground or not to ground
Don makes an excellent point. And a really cheap and effective way to do it is to put a resistor from each antenna "hot" side to ground. For a 50-ohm transmission, 500 to 1000 ohms is fine. That will bleed off any charge building up on the antenna but will be too high of a value to affect the operation of the antenna. Ron AC7AC -Original Message- Clint, Not OT at all. Many remote antenna switches do it "the easy way", and use SPST relays to switch in the selected antenna - there is no way with that type relay to ground the antennas that are not currently selected. So yes, some type of static discharge device would be beneficial across each antenna connector to bleed off static. Usually a 100 uHy choke (of sufficient current capacity for your power level) or a 2 or 3 watt carbon resistor in the range of 3000 to 30,000 ohms will provide the DC path to bleed off any static charge. Imagine your antenna with a static charge - then you select that antenna - suddenly your transceiver is subjected to whatever charge was on the antenna. Sometimes OK, but other times, not so good. 73, Don W3FPR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
