Oil cooled antenna

The oil actually helps the receive but it does not have any effect on Cooling unless somebody was stupid enough to try to run 10000 Watts through it.
Another thing the oil does is prevent corrosion from happening to the Copper which is a good thing. All the electrical connections inside are submerged in mineral oil which prevent corrosion from occurring to those connections.
You can ignore what they say about gain.

 

In case this starts up arguments I'll take the liberty of reposting Russell Clift' s words of wisdom:
Unlike shiny copper, Aluminum on the outside surface is covered with a thin layer of oxide, Al2O3 (sapphire). This insulating surface is a dielectric much thinner than the skin penetration depth for RF at 27 MHZ yet thick enough to allow surface charge to buildup until it breaks down through the very thin layer of sapphire as the local space charge builds up in voltage. In the wind a never ending source of 'static noise' easily heard especially if the receiver is less than a micro-volt in sensitivity. So yes, it can be proven a copper antenna has much less 'static noise' than an aluminum antenna. That is until chemical corrosion coats the copper with oxide. One conclusion being it pays to keep your copper antenna shiny at all times.

 

the truth is that the oil does nothing. It is not needed, it does really cool anything until you get up to that 4kw limit and then it may help.

Copper used in most antenna coils are enamelled so they don't corrode unless there is an issue with a seal on a loading or it is an open loading coil.

Why is it I don't have this issue on any other band but it must be magic with 11 meters, I had many aluminium 10 meter antennas both on vehicles and setup for the house (my present dipole uses aluminium electric fence wiring and it works just as well as the copper wire I've used for years.

Anyway back to these oil filled loading coils.

I've never seen an improvement in receive. I just never. Transmit nothing gained.

By the way, I discovered a cool antenna in storage this morning, ever hear of a Whiskey Still antenna?

I got it from some guy who claimed to be the first to build them back I think '84 or maybe even '83. I told him we've seen them around for a few years since the mid-70's but he said no one built one like that before. I still bought one to replace the Big Momma I had and it worked well until I pulled the radio out of the pickup and sold the thing - never should have sold it, best truck I owned.

 

The difference would never be noticed in the real world unless the noise floor of the radio itself was dropped to ridiculously low levels such as the radios I have in my possession. Only under those circumstances would you ever notice a difference. Unless your technicians name is Mark Sherman there are certain things in this life that you will never get to experience.
Technically you are correct in that the oil does not directly help the receive. What the oil does do is prevent corrosion from forming at the two critical spots where the connections are made inside the coil and it does prevent corrosion from forming on the outer surface of the copper wire which does reduce static over the long haul. It would be a huge assumption Assuming that there is a plastic coating over the copper wire and I would never make that assumption especially considering the newer antennas are made in China.

 

At Ridgeline all of your observations are to be expected and you would never have witnessed a difference between copper and aluminum based on your receiver sensitivity. So technically this only applies to a small select group of people and the majority of people would never notice a difference

 

The last time I visited Russell Clift at his shop I let him take a peek at one of my HR 2510 radios
( for amusement purposes only )
and he hooked it up to his cheap little B&K Precision signal generator and according to that generator my receiver sensitivity was
-167 DB. His eyes almost popped out of his head when he saw how low it was. I think it was at that point that he understood why I no longer allowed him to work on any of my equipment.
I think the lowest he got was -117 DB
( and he was one of the best technicians in the business)

 

OH I get it, no one else has sensitive radios.

Yep that Sherman guy is so smart that others never done that work on CBs.

Sorry Rabbi, but Sherman isn't the guy I go to nor can he actually be allowed to touch what I have.

I tell you that noise floor isn't all that important. There are a couple other tests that matter much much more.

But see the chances of the oxidation (copper doesn't corrode) has such little effect through the issue of the skin effect where as aluminium is used to prevent any issues from happening in high power applications (CBs are not high power - I'm talking about 20kw plus).

There is more of an issue with the soldered joints within the loading coil going bad with things like water leakage and weather exposure than copper oxidation. Furthermore I only know of one custom antenna that actually used a welding method to stop that joint defects. Those with assemblies that are mechanically connected - rivets or nuts and bolts - still run the risk of corrosion at those joints. Like using stainless steel bolts with aluminium material - it seems to be an issue.

Now if you want to use copper and don't want to have issues with the skin effect of oxidation then you can silver plate it or silver/cadmium plate it. The former still forms an oxidation but the conductivity is much better, so it is a trade off, the latter is a given, it doesn't really corrode.

Well this is the funny part for me, I have really good equipment here, and not just the CB stuff. I just finished buying two radios, one of them is a regular ham radio and the other is something I just loved to have and took a while to get here after I ordered it. Both have -141 dbm noise floor and that isn't the best I have when it comes to noise floors. The funny thing is I also have a Collins radio built in 1952 which has the same noise floor number - it was tested five years ago when it was rebuilt by someone who knows his Collins stuff.

BUT remember the noise floor isn't the important number.

Wow a B&K, most likely not calibrated but I guess that's ok. Still an old design and really doesn't matter.

You DO know what number is more important than the noise floor numbers?

DO you know that mobile hf systems don't need a super low noise floor because of the ambient noise generated within the vehicle by itself is a lot more than the RF noise in many cases PLUS that a mobile system itself has too many variables to say which is better, aluminum/copper, -140/-20 - right?

 

Considering the lack of good technicians if your technician is capable of receiver sensitivity such as what you described we should be promoting his business and referring customers to him instead of some of the other people mentioned in this forum.

 

Nope, Already asked if I could and he said he has enough work that he isn't taking on anything new and asked if I could hold off bring him more of my own stuff to work on.

By the way you didn't answer my question, you speak of the noise floor as important but what other test is really important and never is talked about?