Tube Testing & Curve Tracing

[JMPGuitars]

Here's the final v7 of the FUtracer & official enclosure:

futracer7.jpg

I'd say it came out kinda perty.

[lavrgs]

Agreed

[JMPGuitars]

The scammers/spammers are after my tube tracer stuff now. Check out these lies I received in some SPAM:

We work with tube curve tracer suppliers to increase their customers through lead generation and online campaigns.

For example, a social sharing contest we launched for one of our clients generated them 287 new referrals in 27 days.

Priceless entertainment. There's SO many tube curve tracer suppliers.

[lavrgs]

Today I'm going to retreive the kit from a friend, who needed a project. He soldered all available parts to the PCB so I will start checking. There were a couple items that were back ordered when I bought most of the components. I know have all the parts for the PCB, with one exception; I ordered WIMA caps by cutting and pasting from the BOM and I received the correct value but it came in KING KONG size 9-). I will evaluate my next move on that component. I will review all the other hardware, I recall there were a couple items still to get.
My machine hobby* is currently taking most of my time, so as the master of the "slow build" I will have to put some serious effort into completing the tester.
*https://photos.app.goo.gl/244YnF9ykyUf7mfq7

[JMPGuitars]

Today I'm going to retreive the kit from a friend, who needed a project. He soldered all available parts to the PCB so I will start checking. There were a couple items that were back ordered when I bought most of the components. I know have all the parts for the PCB, with one exception; I ordered WIMA caps by cutting and pasting from the BOM and I received the correct value but it came in KING KONG size 9-). I will evaluate my next move on that component. I will review all the other hardware, I recall there were a couple items still to get.
My machine hobby* is currently taking most of my time, so as the master of the "slow build" I will have to put some serious effort into completing the tester.
*https://photos.app.goo.gl/244YnF9ykyUf7mfq7

lol, yeah, you're definitely the master of the slow build. Did you ever finish your Tremolo TMB?

Which caps do you need? Last I checked, the BOM on Mouser was all good.

[lavrgs]

I have two amp projects that have been on the bench for well over a year...the champ radio - 5f1 circuit going into a vintage 1942 radio...and the TMB
I just ordered the wrong caps...I was going to see if the leads fit into the vias before I order the proper size...EDIT They don't fit not sure how I ended up with those elephant sized caps...

[lavrgs]

All the boards are finished. One question on the Tube board - which fuses are used I have 0.5A and 1.6A were part of the Mouser BOM.
I'm going to assume 22 awg wire for all the connections since that is what the connectors are rated for.
What is the suggested p/n for the ferrite bead on the tube board wiring?

[JMPGuitars]

All the boards are finished. One question on the Tube board - which fuses are used I have 0.5A and 1.6A were part of the Mouser BOM.
I'm going to assume 22 awg wire for all the connections since that is what the connectors are rated for.
What is the suggested p/n for the ferrite bead on the tube board wiring?

The 0.5A are for the two fuses on the main board. The 1.6A are used everywhere else.

I think the ferrite core I use for the anode wire is the FSRH091160RN000T - available at arrow.com.

Thanks,
Josh

[lavrgs]

Is there a bring-up procedure or is it just plug and pray? Dim bulb tester...? Any voltages to check?
Is there any reading material on testing tubes? I don't know Jack, maybe an address?
I'm close to finishing - just cables and LEDs to go
I've downloaded the software - I'll try firing it up - do I need the tester connected or will it start just to see it up?

[JMPGuitars]

The website has all that info: https://futracer.com/curve-tracer/

First calibrate it with the top panel disconnected (calibrate it page).

Then the "Use It" page shows you some basic testing info.

You don't need to do anything fancy for startup, plug and pray is the way. That's what fuses are for!

[lavrgs]

The connectors are "interesting" I like the concept but I didn't know the leads need to get pushed in after soldering...had to go back and adjust the first one I did. Just have to be careful about filling the "trough" too high with wire and solder.

[JMPGuitars]

With the connectors in the BOM, I don't solder them. I either bond the wire, or use pre-bonded wire and then use the pins as intended to compression fit together.

Thanks,
Josh

[lavrgs]

I'm looking for a pic that shows the wiring for the heater psu. Thanks for all the quick responses!

[JMPGuitars]

I'm looking for a pic that shows the wiring for the heater psu. Thanks for all the quick responses!

It says on the heater PSU in and out, and the +/- terminals. The enclosure page has some photos of it, but not clearly what's connected.

[lavrgs]

Doing the initial bring up - no tube board connected. I got the usb beeps I would expect, and the GUI came up but I have odd values compared to the web docs.>> Had to switch to COM4 and I was able to communicate.
I tested the PSU with an external power source and I need to make the cable to connect it to the system
Checking the voltages on the main board
+5>>6.95 OK?
+15 OK
+20 OK
-15 OK
-40 >>-56.4 OK?
When I shut down the GUI it tells me there is an update - any reason to do it now? I'm at V3.06

[JMPGuitars]

That's not okay. I would start by inspecting the board thoroughly. It's possibly you missed a solder joint (or two).

The LM7805 is what gives the +5VDC, and that also effects the negative supply. So I would start there at the LM7805, and make sure everything looks good.

Thanks,
Josh

[lavrgs]

replacing the LM7805 fixed the problem. Now back to the cabling...9-)

[roadshow]

Hi Josh,

I was looking for a list of tubes supported and all I could find was the list on the enclosure.
The 8ET socket shows support for KT88. I presume that the KT66 is supported as well? My take is that the tube selected drives the population of some of the menus and parameters.

Thx,

Bill

[JMPGuitars]

Hi Josh,

I was looking for a list of tubes supported and all I could find was the list on the enclosure.
The 8ET socket shows support for KT88. I presume that the KT66 is supported as well? My take is that the tube selected drives the population of some of the menus and parameters.

Thx,

Bill

The list on the enclosure is what the sockets support without adapters. KT88 is 8ET, and KT66 is 7AC. As the enclosure list mentions, both use the same pinout.

9A: 12AX7, AT7, AY7, 6072, 7025, CV4004, M8137, 6057, B759, ECC81, ECC82, ECC83, etc.
7BD: 6028, 408A, 6AU6, etc.
9AQ: EF80, EF184, EF800, EF811, PF818, W719, Z152, Z179, Z329, Z719, Z749, 6BX6, 6BY7, 6F19, 6GK7, 7ED7, 8D6, etc.
9CQ: EF86, 6J32P, 6267, etc.
9CV: EL84, 6P15, 6P14P, 7189, E84L, CV2975, N709, 6BQ5, etc.
8ET: EL34, 6L6, 5881, 6V6, 6550, 6CA7, 7581, KT88, KT90, KT100, KT120 and all 7AC, 7S, or 8ET base pinout.

Beyond that you make adapters, like I do for sub-mini tubes:

[roadshow]

Thx Josh,

My RCA manual shows the bases for all numbered tubes, but I have no reference for any letter based tubes. Do you know of a reference for that? For example, any data sheet I have for KT66 does not list the base.

Thx.