Re: I’m doing a little survey of people that have rotatable antennas.
It was about 4-5 yrs ago. I checked in my supply cabinet and I have both Krylon and Rust-Oleum. Best guess is Krylon gray primer.
I queried the antenna but go no response :>)
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On Jun 19, 2024, at 4:48 PM, Cliff Sojourner K6CLS via < cls@...> wrote:
From:
Sent: June 19, 2024 4:43:01 PM PDT
To:
Subject: Re: [QRPops] I’m doing a little survey of people that have rotatable antennas.
That's funny!? Exactly what paint was it?? They make so many. On June 19, 2024 4:01:19 PM PDT, HOWARD POMERANTZ < HOWPOM@...> wrote:
Hi Cliff,
As you say it depends on what you are using the paint on. I have an Ed Fong (TJB-1) contained inside a piece of PVC pipe. It was working great until I painted it with a Rust-Oleum spray to blend in and guess what? It stopped working. When I removed the paint it worked as advertised. The product I used had metal in the paint matrix.
Moral of the story: caveat emptor
?
On Jun 19, 2024, at 11:42 AM, Cliff Sojourner K6CLS via < cls@...> wrote:
I'm going to be a wet blanket here.? There's a lot of superstition and folklore but very few objective measurements about metal in paint being RF effective.
This matters a lot to hobby rocketry, using 434MHz and 915MHz trackers and telemetry, inside painted airframes.
My practical experience is: very little effect of paint.? Experiments include white paint (titanium dioxide), heavy build primer (lots of zinc), black (carbon for color), and lots of combinations in between.? Not much 70cm signal attenuation, nothing really measurable.
We've also done experiments with airframe materials, including cardboard, FR4 fiberglass (similar to the pultruded dowels for hex beams), epoxy and E glass layups, not colored and colored, and carbon fiber layups.? Of those, only real carbon fiber showed any attenuation.
None of the paints or airframe materials showed any DC conductivity (ohms) at all.
Some years ago, a ham 3D printed a small microwave (mm wave actually) dish, and used a special expensive high-metal paint.? That worked, to the limit of the 3D printed shape.? The paint layer was very thin and I'd expect because of surface effect it would not be effective at lower frequencies.
So yeah very special high metal paints can have some RF effect if you go to enough trouble.
Next step:? trying to organize some calibrated test equipment and both an anechoic chamber and outdoor range.
Cliff K6CLS CM87
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Re: I’m doing a little survey of people that have rotatable antennas.
From: Cliff Sojourner <cls@...>
Sent: June 19, 2024 4:43:01 PM PDT
To:
Subject: Re: [QRPops] I’m doing a little survey of people that have rotatable antennas.
That's funny!? Exactly what paint was it?? They make so many. On June 19, 2024 4:01:19 PM PDT, HOWARD POMERANTZ <HOWPOM@...> wrote:
Hi Cliff,
As you say it depends on what you are using the paint on. I have an Ed Fong (TJB-1) contained inside a piece of PVC pipe. It was working great until I painted it with a Rust-Oleum spray to blend in and guess what? It stopped working. When I removed the paint it worked as advertised. The product I used had metal in the paint matrix.
Moral of the story: caveat emptor
?
On Jun 19, 2024, at 11:42 AM, Cliff Sojourner K6CLS via < cls@...> wrote:
I'm going to be a wet blanket here.? There's a lot of superstition and folklore but very few objective measurements about metal in paint being RF effective.
This matters a lot to hobby rocketry, using 434MHz and 915MHz trackers and telemetry, inside painted airframes.
My practical experience is: very little effect of paint.? Experiments include white paint (titanium dioxide), heavy build primer (lots of zinc), black (carbon for color), and lots of combinations in between.? Not much 70cm signal attenuation, nothing really measurable.
We've also done experiments with airframe materials, including cardboard, FR4 fiberglass (similar to the pultruded dowels for hex beams), epoxy and E glass layups, not colored and colored, and carbon fiber layups.? Of those, only real carbon fiber showed any attenuation.
None of the paints or airframe materials showed any DC conductivity (ohms) at all.
Some years ago, a ham 3D printed a small microwave (mm wave actually) dish, and used a special expensive high-metal paint.? That worked, to the limit of the 3D printed shape.? The paint layer was very thin and I'd expect because of surface effect it would not be effective at lower frequencies.
So yeah very special high metal paints can have some RF effect if you go to enough trouble.
Next step:? trying to organize some calibrated test equipment and both an anechoic chamber and outdoor range.
Cliff K6CLS CM87
|
Re: I’m doing a little survey of people that have rotatable antennas.
Hi Cliff,
As you say it depends on what you are using the paint on. I have an Ed Fong (TJB-1) contained inside a piece of PVC pipe. It was working great until I painted it with a Rust-Oleum spray to blend in and guess what? It stopped working. When I removed the paint it worked as advertised. The product I used had metal in the paint matrix.
Moral of the story: caveat emptor
?
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Show quoted text
On Jun 19, 2024, at 11:42 AM, Cliff Sojourner K6CLS via < cls@...> wrote:
I'm going to be a wet blanket here.? There's a lot of superstition and folklore but very few objective measurements about metal in paint being RF effective.
This matters a lot to hobby rocketry, using 434MHz and 915MHz trackers and telemetry, inside painted airframes.
My practical experience is: very little effect of paint.? Experiments include white paint (titanium dioxide), heavy build primer (lots of zinc), black (carbon for color), and lots of combinations in between.? Not much 70cm signal attenuation, nothing really measurable.
We've also done experiments with airframe materials, including cardboard, FR4 fiberglass (similar to the pultruded dowels for hex beams), epoxy and E glass layups, not colored and colored, and carbon fiber layups.? Of those, only real carbon fiber showed any attenuation.
None of the paints or airframe materials showed any DC conductivity (ohms) at all.
Some years ago, a ham 3D printed a small microwave (mm wave actually) dish, and used a special expensive high-metal paint.? That worked, to the limit of the 3D printed shape.? The paint layer was very thin and I'd expect because of surface effect it would not be effective at lower frequencies.
So yeah very special high metal paints can have some RF effect if you go to enough trouble.
Next step:? trying to organize some calibrated test equipment and both an anechoic chamber and outdoor range.
Cliff K6CLS CM87
|
Re: I’m doing a little survey of people that have rotatable antennas.
I'm going to be a wet blanket here.? There's a lot of superstition and folklore but very few objective measurements about metal in paint being RF effective.
This matters a lot to hobby rocketry, using 434MHz and 915MHz trackers and telemetry, inside painted airframes.
My practical experience is: very little effect of paint.? Experiments include white paint (titanium dioxide), heavy build primer (lots of zinc), black (carbon for color), and lots of combinations in between.? Not much 70cm signal attenuation, nothing really measurable.
We've also done experiments with airframe materials, including cardboard, FR4 fiberglass (similar to the pultruded dowels for hex beams), epoxy and E glass layups, not colored and colored, and carbon fiber layups.? Of those, only real carbon fiber showed any attenuation.
None of the paints or airframe materials showed any DC conductivity (ohms) at all.
Some years ago, a ham 3D printed a small microwave (mm wave actually) dish, and used a special expensive high-metal paint.? That worked, to the limit of the 3D printed shape.? The paint layer was very thin and I'd expect because of surface effect it would not be effective at lower frequencies.
So yeah very special high metal paints can have some RF effect if you go to enough trouble.
Next step:? trying to organize some calibrated test equipment and both an anechoic chamber and outdoor range.
Cliff K6CLS CM87
|
I will be operating FD from the back yard.? I will be QRP, single op, using KI6DS as my call.? Hope to work you.
Doug
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The annual ARRL FD contest? exercise is this weekend.? I
will be operating from Maryknoll, near the pagoda roof line you have
seen from 280 a mile north of 85.? Grid CM87XI00GC
You're all welcome to some full size antennas put up.
With perfect planning, equipment will arrive around 11 on Friday, but being FD, if might be later.
On Wednesday, June 19, 2024 at 08:58:10 AM PDT, Hiroki Kato <hiroki@...> wrote:
I will be at the Baylands starting with lunch. Hope to see many of you.
Hiroki AH6CY
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Re: I’m doing a little survey of people that have rotatable antennas.
Good news....no metal in the paint. Thanks for thinking of this. I appreciate your comment. See below.
?
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I will be at the Baylands starting with lunch. Hope to see many of you.
Hiroki AH6CY
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Re: I’m doing a little survey of people that have rotatable antennas.
Metallic colored paints often do have metal particles.? I have used a certain zinc spray paint.? I recall it labeled as cold galvanizing.
But I would think that most paints do not have metal particles.?
Good that Joy has time to get the real answer and the paint maker has responded with useful info.? I would probably have rushed ahead.
Now I recall a DIY antenna with fiberglass rods which I painted a flat grey.? I wasn't aware of any problems.?
On Tuesday, June 18, 2024 at 03:35:28 PM PDT, Joy Rabins <doghouse3@...> wrote:
Thanks Howard. I did email the manufacturer and asked what to paint fiberglass with and he gave me their recommendation but I never told them the ?application had to do with an antenna and never mentioned anything about metal in the paint. I did forward the manufacturer‘a recommendation to the hex company, kio, and he thanked me but also never said anything about metal in the paint. I’ll follow up with the paint company. Luckily we are slow pokes here so I haven’t started painting. We are still scratching our heads on how to get it up on the mast. Thanks Joy
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Re: I’m doing a little survey of people that have rotatable antennas.
Thanks Howard. I did email the manufacturer and asked what to paint fiberglass with and he gave me their recommendation but I never told them the ?application had to do with an antenna and never mentioned anything about metal in the paint. I did forward the manufacturer‘a recommendation to the hex company, kio, and he thanked me but also never said anything about metal in the paint. I’ll follow up with the paint company. Luckily we are slow pokes here so I haven’t started painting. We are still scratching our heads on how to get it up on the mast. Thanks Joy
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eBay item - Fwd: spy radio: 1 NEW!
In case anyone is interested. This is a spy radio used by the CIA. CW only, about 15 watts, Xtal controlled, useable on 40 and 80m ham bands. For what it is, it is a fair price, IMO.
I own one and works well.
Hiroki AH6CY Begin forwarded message:
Subject: spy radio: 1 NEW!
Date: June 18, 2024 at 1:26:39 AM PDT
| | | Buy it now: $850.00 | | 100%?positive feedback |
| |
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Update your email preferences? You are receiving this email based on your eBay account preferences. To change which emails you receive from eBay, go to??in My eBay.? |
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Re: I’m doing a little survey of people that have rotatable antennas.
Joy,
Be care what paint you use for a particular application. Most spay paints contain metal particles to help it adhere to the medium you are painting. Works great for metal but if you have a fiberglass mast that you do not want to be a conductor check with the paint manufacturer to ensure there is no metal in the product that you intend to use.
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On Jun 14, 2024, at 7:57 AM, Peter Mahowald < petek6tj@...> wrote:
Consider grey paint, less visible On Jun 14, 2024, at 7:44?AM, Cliff Sojourner K6CLS via < cls@...> wrote:
Joy, about painting;
Any kind of enamel will work to protect the fiberglass rods from UV.
Go to OSH and get a big can of their brand spray black enamel.? Gloss or flat, your choice; heck you can use white or green or brown if you want.
Details:
If you are not comfortable with spraying and the resulting over spray, get an 8oz can of enamel and a brush.
The fiberglass likely has some mold release (PVA) on it from the factory.?? You can feel it, it's a little slippery.? It?? is best removed chemically, I use Zep brand orange degreaser spray.? The fiberglass will be squeaky clean.
If the rods have any splinters (be careful!) those can be tamed.? use a green Scotch Brite scrubby and some water.
Cliff K6CLS CM87 On June 14, 2024 7:10:03 AM PDT, Joy Rabins < doghouse3@...> wrote:
Paul, The way my "MacLogger DX" logging program works is, it gives you a spreadsheet like list of spots from its spot cluster. When I select a spot from this list, it tunes the radio to the selected frequency and mode that is displayed on the cluster list. I think the way it works is if you have a third party controller connected, in addition to switching to the correct band and mode it would also turn the rotor to that spot information listed as their address from the spot. I think it gets most of the ?information from QRZ. Now, if the cluster spot that is selected ?is the home address coordinates, and they are working portable somewhere, all bets are off and it won't work because the rotor control will be turning the antenna to the home address ?coordinates listed in QRZ which will be wrong........unless of course, they are working portable from their backyard ;)?
This is more than I probably need to get started and can always add it later.?
This is all new to me. I have never even seen a station that has rotor set up in action, hence all the questions.?
The hex beam arrived yesterday. I don't know exactly what I was expecting but i thought it would be in a lot bigger package. But most of it is air when it's deployed.
Dick told me to make sure I painted the spreaders before it goes up. The KIO website suggested Rustoleum black flat spray paint- two coats. Have you ever looked at the Rustoleum ?website? Even if I choose black for a color, they have a gazillion choices of products. Everything from painting motors to plastic. I sent their product support a message asking which product to use to paint fiberglass, so I'm waiting for their responce. Once this baby goes up......it is not coming down because I used the wrong paint.?
Expect more questions.
Joy
N6GO
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Hi Dave,
Here is the solder gun I mentioned on Friday. It is good for people who have mild tremors.
Here’s the Amazon link. There are other brands available on eBay etc.
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Hi Paul: ? ? ? On the FET thing: a friend named Steve, who's input I value highly, recently suggested FET Avalanche Breakdown should be like a reliable zener, with wattage-rating equal to the FET's power dissipation rating.
According to our recent findings, apparently a 1 watt zener has proven more robust than a 100 watt FET,?when overvoltage?conduction occurs at RF frequencies.?
On a sidenote, 30 years ago, I did some linear shunt regulators, 15V to 15KV range, using series strings of FETs. They worked great. Presumably they're still controlling anode voltages on 352 Klystrons, for the Accelerator.
Strangely, I tried making linear regulators with FETs more recently. I found some FETs weren't reliable. Others were. Then we found linear-rated . Apparently, with? the cellular structure of many FET?dies, power dissipation in the linear region doesn't spread uniformly across the die. It takes special construction to make this work right.?
I bet we're learning empirically, uniform distribution of power dissipation across an FET die is also a problem at RF frequencies, when using the Avalanche Mode Breakdown mode. My pal Steve will be eager to learn about this.
--Jeff
This Friday, I will be preparing for the ARRL FD contest exercise.? QTH is Maryknoll.? We have a nice flat field next to the building with pagoda roofline which you have seen from 280 a bit north of 85.
Everyone is welcome to drop by.
Friday is mostly setting up antennas too big for Baylands.? The operating time is from 11:00 PDT Saturday to 11:00 Sunday.? All bands from 160 to 432 will be used.
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On Monday, June 17, 2024 at 10:59:41 AM PDT, Doug Hendricks <ki6ds1@...> wrote:
What call will you be using??
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What call will you be using??
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This Friday, I will be preparing for the ARRL FD contest exercise.? QTH is Maryknoll.? We have a nice flat field next to the building with pagoda roofline which you have seen from 280 a bit north of 85.
Everyone is welcome to drop by.
Friday is mostly setting up antennas too big for Baylands.? The operating time is from 11:00 PDT Saturday to 11:00 Sunday.? All bands from 160 to 432 will be used.
|
Re: I’m doing a little survey of people that have rotatable antennas.
Let's do the glow in the dark thing for Halloween!
On June 16, 2024 9:12:50 AM PDT, Joy Rabins <doghouse3@...> wrote:
Cliff, I think Peter was talking about more keeping it 'invisible" by using they grey color rather than protecting it from UV. ?I opted to get the flat black as was suggested by the hex maker.?
I did see some glow at night paint that I thought might be interesting. It would be especially exciting to see a 20 foot upside-down spider web glowing in the dark above the roof in the sky at Halloween. My husband nixed that idea.?
Joy
N6GO
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Re: I’m doing a little survey of people that have rotatable antennas.
Cliff, I think Peter was talking about more keeping it 'invisible" by using they grey color rather than protecting it from UV. ?I opted to get the flat black as was suggested by the hex maker.?
I did see some glow at night paint that I thought might be interesting. It would be especially exciting to see a 20 foot upside-down spider web glowing in the dark above the roof in the sky at Halloween. My husband nixed that idea.?
Joy
N6GO
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Re: I’m doing a little survey of people that have rotatable antennas.
I don't think color matters much for UV protection.? I had a 20 year old fiberglass antenna painted OSH white in perfect condition.
On June 15, 2024 8:28:17 AM PDT, Paul AA6PZ <aa6pz@...> wrote:
Customer support that actually answers the customer's question!? Amazing!
My speculation is that black will do the best job of absorbing light and protecting the fiberglass.? I would suggest a final color of light grey or sky blue to make it less visible to non-hams.? Follow the label directions of time between coats.
On Friday, June 14, 2024 at 10:38:05 PM PDT, Joy Rabins <doghouse3@...> wrote:
KIO recommended Rust-Oleum in a flat black to paint the spreaders. The Rust-Oleum website had a gazillion paints to choose from so I sent a message for their recommendation for painting fiberglass and below is what they sent me, they recommended an enamel paint which is also what Cliff had recommended.?
"Hello Joy,
Thank you for contacting Rust-Oleum Product Support.
The best product we have that can be applied direct to fiberglass is the Stops Rust Protective Enamel. We do offer the spray in flat back, and two coats covers 6-10 sq ft. I have attached a link that will take you to this product on our website:
If you have any additional questions or concerns, please do not hesitate to contact us!
Jacob S.
Product Support Representative
Rust-Oleum Corporation
Phone: (866) 580-4376
Fax: (866) 787-2150"
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Cliff Sojourner K6CLS
Jeff Reagan
?
Glad to help! The Stops Rust Protective Enamel does not have any metals in it.?
?
If you have any additional questions or concerns, please do not hesitate to contact us!
Jacob S.
Product Support Representative
Rust-Oleum Corporation