Progress has been made on the Tractor Beam (phaser) and is on schedule for release probably in 7-10 days. I got the audio board populated after waiting on a couple parts from Mouser. The Tractor Beam was originally called the Enterprise and is built on the same board. There are a few value tweaks from the Enterprise so the pot values here are not all accurate.
This will be a difficult build, but if you have done one of the VFE already it shouldn't be too bad. There is on electro that has to be soldered in parallel with a Zener (top right). There are three resistor networks (two 10k and one 22k). It also requires four matched 2n5952 FETs. I actually had a set I previously matched for a different project and was no longer using. The doc will have instructions on how to match FETs (I think I may have already covered this in the Phase 90 doc). The "B10k" is actually 1k now, and only having 2k on-hand I soldered in another 2k resistor in parallel with it.
Also, I have a FET matching board I may just put up on OSH Park. It was supposed to be part of a small batch of utility boards I was going to offer for sale but I never got around to it.
Anyway, to do: build the switching board and test it out. My prototypes for the re-designs of the VFE switching board will be here in a few days so I think I will wait and test one of those out with this build.
Decent!
Brian,
Anyway you might beable to post the board page with all the parts like you did with the Choral Reef? If you can't it's no big deal. Thanks. (//)
awesome, will keep watch
What Function F(x) board is that in the background?
Quote from: Ralfg on August 14, 2017, 01:49:28 AM
What Function F(x) board is that in the background?
should be the clusterfuzz.
that phaser layout is really closely packed...
That looks really cool. Never used resistor array's before. Looks like a really smart way to save a lot of space on a really packed board.
Here is the draft of the Tractor Beam BOM/Shopping list. I have a bit of debugging to do on my build but I believe this list is accurate.
As always, thanks Brian!
Thank you!
Cheers!
The 1.43K resistor that you link to mouser is way too big. It's a Vishay Dale that's the same size as a 1/2 watt Xicon. I did a quick search but couldn't find anything suitable. I'll probably get some smd resistors of that value and make them work. After all, it's diy.
Huh - 8mm. That is a bit long (though they could be made standing). Here are two 6mm ones (still a bit long):
http://www.mouser.com/ProductDetail/Vishay-Dale/RN55D1431FRE6/?qs=sGAEpiMZZMu61qfTUdNhGzQiLrTi4xBWc4N7jZ0yHC0%3d
http://www.mouser.com/ProductDetail/Vishay-Dale/RN55D1431FB14/?qs=sGAEpiMZZMu61qfTUdNhG3gu04FpCMicro03p17NpK8%3d
Thanks for posting that. I forget which one I used...I'll have to look.
Have you made any progress with the debugging of your build Brian?
Just in case you read this, thanks.
I have been really enjoying these VFE builds.
Quote from: Jules on October 07, 2017, 09:47:55 AM
Have you made any progress with the debugging of your build Brian?
Just in case you read this, thanks.
I have been really enjoying these VFE builds.
Yeah, it's pretty much done. Should be releasing later this week. Turns out it was user error. I'm the user.
That's a sexy phaser
Great! Thanks a lot.
Is this how to assemble your own resistor arrays for the Tractor Beam?
*edit* Updated. Thanks, WormBoy!
(https://i.imgur.com/pp9VHAU.jpg)
Isolated looks good. For bussed, the bus needs to be directly connected to pin 1, so basically you would replace one of the outer most resistors with a jumper. As Brian explained in another thread: it does not matter whether that's the first or the last (quirk of the tractor beam design: both the first and the last pin of the bussed array are connected to ground, so one resistor is in fact unused). I would always quickly check the board with a DMM, just to make double sure ;D.
Many thanks, I just received my boards today!
I didn't notice the Tractor Beam listed on the switching board doc..... what voltage zener do I need?
Also want to double check I need the charge pump chip. Thank you very much.
The Tractor Beam is on the last page of the switching board doc, in the schematic. States a 16v zener, but if you only run it on 9v, you can easily use something lower (it is only there to protect against overvoltage). The charge pump is in the photo in the TB build doc, and if you look at the opamp voltages, it is indeed used 8).
Thanks, Wormboy! I might need glasses.
When I'm matching the JFETs, what is the tolerance? How close do they have to be?
Quote from: mark123 on November 11, 2017, 01:22:26 PM
When I'm matching the JFETs, what is the tolerance? How close do they have to be?
as close as possible
while we waiting Brian project jfet matcher, you can view NomNom docs
Quote from: 287m on November 11, 2017, 02:20:49 PM
... you can view NomNom docs
I saw that mentioned but didn't know what it meant. I Binged it and figured it. Thanks.
From the Nomnom doc:
QuoteYou want to find the closest matching voltage readings on these transistors. At least within 5% of one another, although I generally shoot for 1% or less. So, if a device reads 0.75vDC, I would look for another one that measures 0.74 to 0.76v.
Exactly what I was looking for. Since we're looking at Vgs I'm just thinking of picking up a semiconductor analyzer.
The Tractor Beam uses the TC7662B and the low ESR Electrolytics, correct? It's not listed in the switching board "Used With" column but it is in the picture of the doc.
Correct.
*disregard*
Brian:
I received two Tractor Beam pcbs from you the other day (in a timely manner, as always). The first Note in the Tractor Beam build document states: "This project is built on the 'Enterprise' PCB... with a few modifications." I'd be very interested in learning what those "modifications" were. I've searched for the original build documents (and Bill of Materials) for the Enterprise, but have been unsuccessful finding them. My question for any readers of this thread is: Does anyone have the original documents, including the schematic, for the Enterprise circuit?
Based upon audio clips I've been able to find, I still prefer the sound of the Enterprise, so would most like to build that circuit. I realize that sound is very subjective and that much depends upon recording techniques and quality, but I've just been less impressed with what I'm hearing from the Tractor Beam circuit, as compared to the Enterprise circuit. Be that as it may, any help finding the original Enterprise plans would be greatly appreciated.
Thanks