Hi David
Yes I used Double sided tape to hold the alum in place.
The hysteresis in the steel needs to be reduced. My first try was double sided 2oz copper PCB and it was better, however the cost was higher than I needed. I tried .031 alum witch was very good, and then used .020 alum. You need to run your own tests as your coil may not be air and the amount of linearity improvement from external steel may not yield any improvement.
Duke
Yes I used Double sided tape to hold the alum in place.
The hysteresis in the steel needs to be reduced. My first try was double sided 2oz copper PCB and it was better, however the cost was higher than I needed. I tried .031 alum witch was very good, and then used .020 alum. You need to run your own tests as your coil may not be air and the amount of linearity improvement from external steel may not yield any improvement.
Duke
Paint the steel. Use a primer and two finish coats. If in a humid environment use a primer containing aluminum.
To paint galvanized steel you may need to lightly sand it first or get a primer made for galvanized metal.
Simon, I'm afraid that you are exaggerating again 😉 What is the voltage of a galvanic cell made with zinc and aluminum at standard conditions? | Socratic
Aluminum -1.67, zinc -.76, Iron -.44 Depends on the process used.
But the galvanneal last measured here was 1.54 volts. Which I suspect means tin was present, or there was more alloy element in the aluminum that screwed things up.
The other issue for a case is that it probably runs at a bit above 25C.
One of the equipment manufacturers that I use regularly changed to galvanneal steel, hence the measurement resulting from the gear being racked up with other folks stuff. (Well above 25C.)
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We ran into same issue for a accelerator Source development experiment. they installed a row of racks (several rows, actually) and later discovered dc potentials in data. One of the co-ordinators told me about this and asked if I knew why or where it was coming from. I figured that it was same issue - galvanic action. I suggested they check for potentials between the racks. yes, it was there but why. I said to ground all the racks together. They did and of course potential differences went to zero. Then I added a way to tie the rows of racks together in a way that gave low r and low L and tie into building ground. he took it back to the staff and later was told by coord they accepted my solution and at added cost and time to their project - they were going to do it. No more issues.
All situations are unique but maybe this gives you another path to your solution.
THx-RNMarsh
All situations are unique but maybe this gives you another path to your solution.
THx-RNMarsh
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I’ve used this material sandwiched between metals to good effect for vibration damping.
Edit: my use case was in a server room filled with raid enclosures.
Worth exploring if it would suit your use case.
http://multimedia.3m.com/mws/media/96388O/3mtm-damping-foil-2552.pdf
“3MTM Damping Foil 2552 consists of a room temperature pressure sensitive viscoelastic polymer on a dead soft aluminum foil and is designed for application to vibrating panels and support members. The combination of viscoelastic polymer and an aluminum foil backing (a constrained layer damper, or CLD) has proved to be a unique construction with exceptional ability to control resonant vibrations in the temperature range of 32° to 140°F (0° to 60°C), with survivability from -25° to 175°F (-32° to 80°C).”
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Kapton tape gap, albeit completely isolating the two parts except through the screw holes, would be more than conformal and probably as thin as the paint itself (~4 thou or 100 um).
Billet aluminum if you must, copper would have the most marginal of benefit, before looking at the CuS vs Al2O3 layers that would immediately develop.
But I'd be more worried about getting the wiping spring flanges to ensure the Faraday cage is complete, no?
Ed -- any clear sign of corrosion of Alu-front steel-body? I could see it happening in marine environments where you can get some electrolytes into the mix. (Salt water)
Derfy,
In large structures like loudspeaker clusters that detail is required by code. In gear we have leftover from radio stations some gear is corroded. That is usually from the transmitter hut as they often have no supplemental heat.
In large structures like loudspeaker clusters that detail is required by code. In gear we have leftover from radio stations some gear is corroded. That is usually from the transmitter hut as they often have no supplemental heat.
Richard,
Are the isolation transformers you used in your designs of the HTPS 7000 and MkII the High type that Demian discussed above? Can they be used here?
Demian,
From the schematic you posted 700 posts ago, what value were the resistors and caps in the top half of your schematic?
That way I can build it with Multisim and check results.
Cheers,
Are the isolation transformers you used in your designs of the HTPS 7000 and MkII the High type that Demian discussed above? Can they be used here?
Demian,
From the schematic you posted 700 posts ago, what value were the resistors and caps in the top half of your schematic?
That way I can build it with Multisim and check results.
Cheers,
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Dear Chalky,
Please tell us which oscillators were mentioned earlier in the thread. As there are more than 7000 posts it could be difficult for someone to find (me included).
Cheers,
Post Script -
@Demian I found the link but lost it. Can't seem to find it again.
Hello Sync,
It's here:
Assembled Low Distortion Audio Range Oscillator 1KHz Sine Wave Signal Generator | eBay
If you fancy soldering it yourself, he's also offering bare PCBs.
Regards,
Braca
It's here:
Assembled Low Distortion Audio Range Oscillator 1KHz Sine Wave Signal Generator | eBay
If you fancy soldering it yourself, he's also offering bare PCBs.
Regards,
Braca
Thanks DNi, Chalky,
That's not bad...I've got one of victor's and modded the HP339A. victors was -160dB = .000001% I want to say -163dB but calc doesn't work that low. HP339A was -123dB = [FONT=Arial,Helvetica,Sans-serif][FONT=Arial,Helvetica,Sans-serif][FONT=Arial,Helvetica,Sans-serif].0000562 % (Possibly -125dB ran out of meter.)
I guess I don't need another one. I did see something that caught my interest as some issues come up with multi-tone testing.
something similar to this:
SigGen1:-----50Ohm----->25ohm\_________RL___________>DUT
SigGen2:-----50Ohm----->25ohm/-(NoLead)-\|/ [gnd] [/FONT][/FONT][/FONT]
That's not bad...I've got one of victor's and modded the HP339A. victors was -160dB = .000001% I want to say -163dB but calc doesn't work that low. HP339A was -123dB = [FONT=Arial,Helvetica,Sans-serif][FONT=Arial,Helvetica,Sans-serif][FONT=Arial,Helvetica,Sans-serif].0000562 % (Possibly -125dB ran out of meter.)
I guess I don't need another one. I did see something that caught my interest as some issues come up with multi-tone testing.
something similar to this:
SigGen1:-----50Ohm----->25ohm\_________RL___________>DUT
SigGen2:-----50Ohm----->25ohm/-(NoLead)-\|/ [gnd] [/FONT][/FONT][/FONT]
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They show passive resistive summation of two generator outputs for IM-free twin tone testing.
Isnt that osc spec'ed as 0.1%
I have victors since I first found him on eBay.... doesn't measure that low.
Where do you get those distortion numbers???
THx-RNMarsh
Is Victor's oscillator still available for sale anywhere? The old ebay links are expired, and there don't seem to be any new auctions.
If not, are there any other oscillators available that perform on a similar level?
Lastly, if I have to bite the bullet and build Victor's oscillator from scratch (which will easily take me a weekend), are there any construction tips and pitfalls to avoid?
Thanks
If not, are there any other oscillators available that perform on a similar level?
Lastly, if I have to bite the bullet and build Victor's oscillator from scratch (which will easily take me a weekend), are there any construction tips and pitfalls to avoid?
Thanks
Please PM me. The oscillators are still in production in small quantities. mainly by request.
Victor.