Stainless steel stock pot

If you can get good sealing on the lid, and get signals in and out.

Something like bulkhead-mount BNC F-F adapters for RF, and some feedthrough caps for slower stuff.

I have a thousand or so Soviet 10 nF feedthroughs that I got on eBay long ago--since I haven't sent your scintillator yet, I'll toss a handful into the box.

Cheers

Phil Hobbs

Plain old soft tin-plate steel cans, like popcorn treats and saltines come in, are good; any decent HVAC shop can bend up a galvanized box for you, and at 100 MHz the seams shouldn't be a major problem. A big stock pot is intermediate-sized by comparison. If you can put battery power inside the box, and avoid DC/DC converters or clocked logic, that's a win.

Yes, but not any help for magnetic fields.

You could seal the lid fairly well with a wide strip of copper or aluminum tape, like the stuff sold at Lowes.

And use it to make chicken broth. No canned junk approaches good home-made broth.

Too bad it won't solder, but you can install SMA or BNC connectors.

whit3rd snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

Without any rf gasketing between the pot and the removeable lid, you may want to buy a roll of copper tape to seal it up with. Tape it up after closure remove after testing.

John Larkin <jlarkin@highland_atwork_technology.com> wrote in news: snipped-for-privacy@4ax.com:

He could line out the pot with 2 inch wide strips of Mu metal. Even transformer lamination media would work.

Thanks for the reply.

Amazon reviewers complain the lid is warped, but it could probably be straightened. Maybe a weight on the lid might help, and some RF gasketing.

I was planning on BNC's, but the shielding on RG-58 is not very good:

"The state-of-the-art for RF leakage of flexible cables is given as nominally –40 dBc for a single round wire braid, RG-8 and RG-58, and –60 dBc for double braid outer conductors", from

Thanks for the news on the scintillator. I have some good information on getting it up and running that I will put in a separate post. I know everyone is just dying to learn how much radon gas is in their basement.

Let me know how much it costs so I can send you the money.

Thanks,

Mike

Thanks for the info. There will be some noisy things inside the pot, but it's the outside interference that will be difficult. There's a FM station not far away that obliterates all measurements.

fredag den 15. juli 2022 kl. 22.20.18 UTC+2 skrev John Larkin:

with a more aggressive fluss stainless solder easily with a normal soldering iron and solder

but it is probably not easy to something as substantial as a pot hot enough without melting the connector

much easier to get some of these:

Is there a reason why you're not considering paint cans?

Or, have the lid brazed into its seat; build a bolt-able flange door into the flat kettle bottom, if easy entry is required. A domed lid wouldn't be easy to seal. I wonder if a salt-water bath containing the lid would be good enough conductivity, just drop the kettle on top of that... quick and dirty.

There once was a reciprocating mechanism to be fitted to a motor, that we just terminated in a brass cup. The motor got a brass ball, and we soft-soldered 'em to connect (and disconnected with a torch). We liked rigidity with minimal moving mass.

Thanks for the link on SMA.

The problem with RG-58 is it only gives 40-60dB of attenuation to leakage:

Mike

Thanks for the idea. There's plenty of RF gasket available.

It's really hard to shield a substantial volume from low frequency mag fields. A chunky steel Hoffman box is basically transparent. Mumetal foil is useless.

Thick copper eddy-current shielding sort of works, but that ss pot won't do much.

Those are cool. You can screw an SMA lowpass filter or attenuator on one side for better isolation.

Tinned braid coax, semi-hardline, is great. ebay has assortments, probably pulled from old RF gear or leftover custom stuff.

If your gizmo will fit, gallon paint cans are a lot cheaper and have really excellent RF sealing.

Cheers

Phil Hobbs

Nah, no worries--it's very short money. We techies have to stick together. I'll send it Monday.

Cheers

Phil Hobbs

That's great news. Thanks Very Much!

For anything that had to leave the lab without a red face, I've resorted to surplus steel ammo boxes. The contacting surfaces can be ground and there's plenty of force-fit area in the hermetic gasket to include em-compatible material.

RL