My Etherwave PCB

"Hello! I've been reading this thread and researching the Etherwave. I want to try the pcb layout provided and I'm deciding if I should do the single or double sided board. Is it confirmed that the double sided board works as well? As many others I am trying to find suitable variable inductors. Any recommendations on available variable inductors? I have been looking at the 100uH Toko A7BRS-T1040Z which Maarkaus stated he was having troubles using, so I'm hesitant on ordering the parts.  Regards, Kolbeinn"

 Hi Soffiuson,

I didn't have much hope with the Toko 100uh, but I did get a good working EW using the slot 10 5 10's. It works quite well, other than the very low volume. I am going to post a sound clip eventually, after I fix that. I have been chasing that issue with this EW for a while now in my spare time

I used the single sided board, and it worked well after I removed the Yet Another Etherwaeve Base Mod. That mod caused some issues.

Next is trying to figure out the volume. Otherwise, the single sided board works.

Thank you for the reply!

I have been searching the usual websites for parts, Digikey, Farnell, Mouser etc but can't seem to find the Slot 10 5 10's. Did you order directly from the Coilcraft website? You wouldn't happen to have a reference number for the parts? I live in Iceland so shipping is a big headache when sourcing for parts. I'm already up to 3 different sources so far for this build...

When removing the YAEWSBM, is it not necessary to change any other part values according to the schematic?

Regards, Kolbeinn

"Thank you for the reply! I have been searching the usual websites for parts, Digikey, Farnell, Mouser etc but can't seem to find the Slot 10 5 10's. Did you order directly from the Coilcraft website? You wouldn't happen to have a reference number for the parts? I live in Iceland so shipping is a big headache when sourcing for parts. I'm already up to 3 different sources so far for this build... When removing the YAEWSBM, is it not necessary to change any other part values according to the schematic? Regards, Kolbeinn"

 Hi Soffuison,

Iceland! That is amazing. Its one of the places I plan to see some day. I am in Canada and suspect its much easier for me to get things.

As for the Slot 10's, yes I ordered them from Coilcraft, and I must say they are the nicest people I have ever done business with. Here is a link to the item in question:

http://www.coilcraft.com/forms/files/en/forms/sample_cart.cfm?action=request_sample&part_number=SLOT%20TEN-5-10&CFID=40828759&CFTOKEN=54471f2873687f73-7EA49A5D-1016-FC16-794A534A177E2D32&jsessionid=843018ce12de4192d49116381e7428574738#

The coils can break when you are adjusting them, so I HIGHLY recommend ordering several as replacements (I broke 2, but had 10 left, so no great loss.) and get the little tool which they sell (cheap). I had originally ordered extra as I have been planning to build one of these for my brother as a gift. Its taking a long time however.

There will be some resistor changes that you will have to do to compensate for the different coils. Thierry, who has some great wisdom on this subject, listed them somewhere on Thereminworld, but I will quote him here:

"R2, R6 and R16: 1.5k instead of 2.2k
R15, R19: 330 instead of 470"

And here is the context / link to thread:

http://www.thereminworld.com/Forums/T/26616/help-finding-parts-for-emetherwave-theremin

I wish you well on your project. I will try to help as I can. I am not an engineer, but I have some experience, now, that I am happy to share (mostly what not to do).

 PS.  sorry I almost missed this part.

"When removing the YAEWSBM, is it not necessary to change any other part values according to the schematic?"

I looked over the schematic in "Hot Rodding your etherwave," and checked to see what differences there are between that and the added YAEWSBM, and it seemed that it was just a simple addition. Quite easy to remove, and fix the traces (in Eagle at any rate) and then jump the gaps with wires. Ugly but worked.

It did work with YAEWSBM but it was more silent then it currently is.

If you get it working let me know!

Great!

Thank you so much for the info. I have etched the pcb and drilled the holes. Now I have to wait for the components to arrive... I will post again when it's working or when I run into troubles :)

Regards, Kolbeinn

"Great! Thank you so much for the info. I have etched the pcb and drilled the holes. Now I have to wait for the components to arrive... I will post again when it's working or when I run into troubles :) Regards, Kolbeinn"

 If you are using the single sided board with the YAEWSBM included, and Eagle software, then one more piece of advice I can give is that when I was placing the resistors, I noticed that some of the resistor numbers (for example the R30 or so) where appearing in switched places with other resistors next to them. Like they were flipped. Just double check before you solder. It will save you much headache. I ended up removing and replacing over a full third of my resistors due to the fact that the designation numbers seemed to be in the wrong placement. 

I am now trying to figure out why the sound is so low, but that is part of the fun. My EW does work but its faint. I have to turn my receiver well past half way, and the antenna can act like a microphone, when I tap it. Not sure why, but I will figure it out.