Once Bit, Twice Shy . . .

[MicMaven]

One thing I’ve noticed with some of these eBay sales is when you go to a PayPal dispute they’ll give you a refund and not bother about the return of the item - ... If the postage back to china is more than the unit cost don’t bother.

Right. That mirrors my own experience. Sometimes the seller will negotiate a discount to compromise the claim and avoid a total loss plus return postage. Postage from China is subsidized by the US Postal Service because China is still listed as a third world developing nation, whereas return postage is at our rates. I always initiate a formal return through eBay's return process which gives the seller three days to negotiate a settlement, or eBay mediates the "dispute." Documenting my case with words and photos, I have always obtained sufficient relief - either a discount, or full refund (with or without a return shipping label at the seller's discretion."

I always document my case with photos and data from the listing showing defect or misrepsentation. Last Summer, I encountered a shipping scam, which required more documentation than usual to resolve in my favor. The seller claimed UPS reported it delivered, when it was, in fact, shipped to another address in my town. UPS records proved it was not addressed to my house, and was a substantially smaller package than a full size waffle iron. The seller next claimed it shipped a second unit, but US Postal Service records proved it was a small, 4 ounce padded envelope addressed to yet another address. not my house. Based on this documentation, eBay disingenuously ruled the package had been delivered to the wrong address by the carrier and issued a full refund! I believe the seller shipped two empty packages, or a couple of rocks, to the wrong address, so it could file an insurance claim for goods lost in transit, while retaining the full purchase price. In any case, I received a full refund and purchased another item one locally. It pays to be diligent and document the whole transaction, just in case.

So ... ya just never know. I am convinced it is best to use eBay's return process, providing a record of all steps in the transaction while binding the seller to play by the rules. James

 

[RoadrunnerOZ]

Here when a package is delivered that can be left without the receiver being present AUSPost take a photo of the package in front of the letterbox and store the JPEG against the tracking number.

 

[MicMaven]

AUSPost take a photo of the package in front of the letterbox and store the JPEG against the tracking number.

Yes, and yet that is hardly evidence or proof of actual delivery. YouTube has a large number of videos depicting delivery people taking a photo of the package on the porch, before picking it up and taking it away. Crazy, but true. This is just one reason many homeowners are installing motion activated video cameras. I want to install a video camera to catch the !%@# dog that poops in my back yard. James

 

[MicMaven]

... go for the refund with the threat of your experienced team of attorneys for whom you will spare no expense (up to and including $27) You need to factor in the costs of the government approved environmental impact study as well.

Good Day, Mr. @RoadrunnerOZ and all. I cannot afford a team of lawyers, having blown the budget on such expensive microphones, so this old retired attorney who now works pro bono (i.e., gratis) negotiated a reasonable compromise settlement and as Mr. RoadrunnerOZ and others predicted, obtained a substantial partial refund, allowing me to keep the grossly misrepresented microphones in perpetuity, and stay within budget!

Epilogue --

In one body, I installed a very low cost circuit and Transound JLI-2590A FET electret capsule, and damped vibration in the plastic body with self-adhesive rubber pads and stuffed it full of foam packing material ... VOILA ! A microphone is born. Total cost around $27. Of course, it LOOKS better and more expensive than it sounds, but I am pleased with the result and enjoyed the adventure along the way.

Ultimately, it works well for the application as the JLI-2590A is especially well suited to speaking at a moderate to close distance. I will use with computer speech recognition software and possibly with an amateur radio transceiver. (The capsule has a meager 80-10,000 Hz useful frequency range, but that is a plus for these particular applications.

The other body will become a non-FET electret condenser with an a used MXL-900 circuit board and true condenser capsule. It has a metal grill, so I will line the body with heavy duty aluminun foil from the kitchen and figure a way to tie it all together. Imagine me considering ideas (and accepting suggestions) on how to make good, assure permanant, continuity between Pin 1 and the aluminum foil . . .

CONCLUSION - So, be ware of false claims of metal microphone bodies and other features of any product on eBay, AliExpress and anywhere else! And yet, the finished product IS a good looking U87-style microphone with ... um ... reasonable performance, considering the nature and cost of its inner workings. Properly shielded, which turns out to be fairly easy and really cheap to accomplish, these plastic bodies are a viable low cost vehicle to build a microphone on the cheap ... and I mean REALLY cheap!

BEST OF ALL, I had fun and learned more about microphones than I knew before from this project, and truly appreciate all of the serious, and sometimes comedic, replies and suggestions I received from the group. Thank you. And I am always open to consider other suggestions and ideas.

James-K8JHR

 

[Khron]

so I will line the body with heavy duty aluminun foil from the kitchen

See if you can get some copper foil somewhere - at least you can solder to that, and get a more reliable connection. Aluminium oxidizes instantly, and the oxide is not conductive.

 

[MicMaven]

See if you can get some copper foil somewhere - at least you can solder to that, and get a more reliable connection. Aluminium oxidizes instantly, and the oxide is not conductive.

Right. So far, the leading contender is to use a very small alligator clip to grab the foil! (Not a good idea, but consistent with the low cost theme of the project ...) James

 

[Khron]

Hey, i said copper foil, not gold leaf

 

[RoadrunnerOZ]

Right. So far, the leading contender is to use a very small alligator clip to grab the foil! (Not a good idea, but consistent with the low cost theme of the project ...) James

A roll of conductive adhesive copper tape costs less than a roll of kitchen foil and would do a lot of mic bodies. Plus it’s easier to install. That and you can solder a ground wire to it thus eliminating the cost of the alligator clip……

 

[RoadrunnerOZ]

Or use overlapping pennies like fish scales all soldered together - then you could literally say “it only cost pennies to shield”

 

[k brown]

How about thin brass sheet stock (K&S Precision Metals, available in most hobby stores - even some better hardware stores; copper isn't stocked as commonly). You can get their copper products thru Amazon.
https://www.amazon.com/s?k=k&s+prec...als+copper,aps,202&ref=nb_sb_ss_ts-doa-p_1_17

 

[RoadrunnerOZ]

How about thin brass sheet stock (K&S Precision Metals, available in most hobby stores - even some better hardware stores; copper isn't stocked as commonly). You can get their copper products thru Amazon.
https://www.amazon.com/s?k=k&s+prec...als+copper,aps,202&ref=nb_sb_ss_ts-doa-p_1_17

The problem with sheet is rolling it to form and getting it inside the mic body while adhesive is in place especially if it’s self adhesive - impossible with contact adhesive. The thinner it is the easier to form but sheet in thin form is super hard to handle. Would be very difficult inside the mic. 1” tape would be the largest - I have 1/4”, 3/4”, 1” and 2” - the 1/4” is fabulous for poking inside cable holes connecting the jack cavity and vol/tone control cavity in a bottom jack guitar, which I try and shield to get total coverage - I smooth that down with a .177 or .25 caliper draw through gun cleaning brush on its cord once the backing is off and the bond started. I leave a length of folded back paper backing inside going backwards to allow drawing off of the backing - tricky but very effective results for single coil pickup gtrs if you’re anal about shielding.
With tape you leave the backing on except for a corner which you turn out so to be grabbable with long nosed pliers or a hemastat, then push the tape down with a finger or wooden dowel with a smooth rounded oval end drawing out the backing as you progress down the strip. I made myself smoothing dollies with dowel 3/4”, aluminium rod 1/2” and a fine 4mm rounded tip stainless finishing rod (for corners in guitar pick cavities). Made them all using my angle grinder taped to my workbench. Total cost of dollies was $3 (the ally and stainless rod I got at a scrap metal guy up the road who gave me the offcuts free - the dowel was an offcut from a wardrobe hanger rod which cost $3 - I had to add a hanger in a wardrobe anyway so used the offcut)

 

[k brown]

The problem with sheet is rolling it to form and getting it inside the mic body while adhesive is in place especially if it’s self adhesive - impossible with contact adhesive. The thinner it is the easier to form but sheet in thin form is super hard to handle. Would be very difficult inside the mic. 1” tape would be the largest - I have 1/4”, 3/4”, 1” and 2” - the 1/4” is fabulous for poking inside cable holes connecting the jack cavity and vol/tone control cavity in a bottom jack guitar, which I try and shield to get total coverage - I smooth that down with a .177 or .25 caliper draw through gun cleaning brush on its cord once the backing is off and the bond started. I leave a length of folded back paper backing inside going backwards to allow drawing off of the backing - tricky but very effective results for single coil pickup gtrs if you’re anal about shielding.
With tape you leave the backing on except for a corner which you turn out so to be grabbable with long nosed pliers or a hemastat, then push the tape down with a finger or wooden dowel with a smooth rounded oval end drawing out the backing as you progress down the strip. I made myself smoothing dollies with dowel 3/4”, aluminium rod 1/2” and a fine 4mm rounded tip stainless finishing rod (for corners in guitar pick cavities). Made them all using my angle grinder taped to my workbench. Total cost of dollies was $3 (the ally and stainless rod I got at a scrap metal guy up the road who gave me the offcuts free - the dowel was an offcut from a wardrobe hanger rod which cost $3 - I had to add a hanger in a wardrobe anyway so used the offcut)

I cut the brass sheet into easier to handle strips with medical scissors and stick into place with coax sealant; the sealant does double-duty of dampening the mic body.
https://www.amazon.com/Fittings-Uni...1701489132&sprefix=coax+sealan,aps,190&sr=8-4
A few dabs of solder to electrically connect the strips.

 

[shabtek]

anybody have use for a few of these bodies? i have 2 to get rid of.




dampening can be done with a spray bottle

Sorry if I revived a zombie thread, but what are some other ways you guys have tried to dampen/deaden....

I cut the brass sheet into easier to handle strips with medical scissors and stick into place with coax sealant; the sealant does double-duty of dampening the mic body.

 

[RoadrunnerOZ]

I cut the brass sheet into easier to handle strips with medical scissors and stick into place with coax sealant; the sealant does double-duty of dampening the mic body.
https://www.amazon.com/Fittings-Uni...1701489132&sprefix=coax+sealan,aps,190&sr=8-4
A few dabs of solder to electrically connect the strips.

How does the brass stick to the coax sealant? Is it double sided or self amalgamating?
The copper foil I use has conductive adhesive so as you overlap the strips you don’t need to solder join them. I meter all point resistance from the earth when shielding and the highest I get is 0.2Ω

 

[k brown]

How does the brass stick to the coax sealant? Is it double sided or self amalgamating?
The copper foil I use has conductive adhesive so as you overlap the strips you don’t need to solder join them. I meter all point resistance from the earth when shielding and the highest I get is 0.2Ω

Coax sealant is a very sticky, rubbery moldable material. Like Blu-Tac, but black and much stickier; rather like black chewing gum, but never hardens or dries out. I just press it into place inside the mic body, then press the brass sheet onto it.

A similar, tougher (but less malleable) industrial material by 3M:
https://www.amazon.com/3M-Safety-22...83&sprefix=3m+mastic+tape,aps,204&sr=8-3&th=1

 

[RoadrunnerOZ]

M

Coax sealant is a very sticky, rubbery moldable material. Like Blu-Tac, but black and much stickier; rather like black chewing gum, but never hardens or dries out. I just press it into place inside the mic body, then press the brass sheet onto it.

A similar, tougher (but less malleable) industrial material by 3M:
https://www.amazon.com/3M-Safety-22...83&sprefix=3m+mastic+tape,aps,204&sr=8-3&th=1

Like mastic I guess - I know they do rubber sealant tape that’s self amalgamating and sticks to itself but has no adhesive and isn’t sticky. I have a 2Kg bag of sticky mastic left over from sealing wall cavities for power and audio cabling in a new recording studio - very sticky stuff, stains your hands but you can’t wear rubber gloves or it rips out the fingertips!