Jeb's Build

[Jeb Jeb]

Indeed!  Actually a little bit of tape isn't a bad idea - for my peace of mind - i'll see how close the last wires and caps get to it - but as you guys say, i'm sure it'll be fine

Yes, looking forward to firing her up after testing in the next couple of days.  Everything is going to sound quite new to me at this point because I only just got the HD650s and don't know them very well yet.  Still first things first, finish the job at hand!

Thanks again all for your help, it's making the whole process very enjoyable, educational and reassuring!

Jeb.

[2wo]

One thing I could recommend before you start the resistances checks, is to practices with your meter a bit. set it to ohm's and connect the leeds together and see what the reading is, it probably won't be 0 but an ohm or two. This is the resistances of the leeds. People tend to stress out if they don't see 0 when called out in the manual. Also if you have any resistors measure them. Check a battery or two for DC and if it convenient check your AC wall voltage.

A little familiarity goes a long way to trusting the reading you get...John           

[Jeb Jeb]

John, that seems like excellent advice.  I'll do just as you suggested when my leads arrive.

Thanks for your thoughts,

Jeb.

[adydula]

Good idea to practice especially if you have never used a meter before, some of the symbols and icons can be confusing, with amps, ohms, volts ac and volts dc.

If you have any resistors lying around you can try to measure them for resistance etc.

If you measure resistance make sure the range your on will allow you to measure it.... if you try to measure say a 21K ohm resistor on a range that only goes up to 20K for example, the reading will be off this scale etc...you need to bump up the range to 20K - 200K for example..

If you measure a resistor on the low end of that range it may be a decimal point readout.... its not that hard, but make sure you use volts ac for ac voltages and the ohms ranges for resistors.... and don't try to measure resistances with power on!

Alex

[Jeb Jeb]

Ahh cool - all good tips Alex.  Yes pretty new to the multimeter thing - the most i've ever done with mine is test a few car batteries.   


I did read forward and go over the voltage and resistance test pages of the manual while I wait for bits to arrive.  Sorry if these are simple questions:

1) The manual recommends to clip the black lead onto terminal 12 for a ground point.  It seems quite tight there and i'm not sure i'll be able to get the clip that I ordered around there securely very easily (should have ordered a smaller one).  Is it acceptable to clip onto a different clearer place like terminal "Earth" on the IEC module, or directly onto the ground-buss wire, or even the empty upper terminal 16 ?

2) For the ideal voltage measurements  the manual also states these were recorded with 119VAC.  Since I'm in UK and using 240VAC does that mean the readings will be different?

3) Since the first part of the voltage checks is to check the tube filaments glow correctly - is the idea to safely prop the plate up (in each corner, or on the sides) high enough so that the 6080 doesn't touch the desk and so that a visual inspection can be made from underneath ?


4)I'm also interested in any tips about general safely probing technique - do you have the crack lengthways or widthways? do you rest your probing arm's elbow on the desk for stability a safe distance from the chassis then carefully go in? or do you keep the whole arm off the desk ?


I finished the last of the wiring today and got the last resistors and caps installed.  I reflowed a number of my early joints and they all look shiny as far as I can tell.    I knew I was getting to the end of my build this afternoon when I realised I was trying to solder in the last capacitor with a piece of the left over ground wire instead of a piece of solder...    



Jeb!

[Strikkflypilot]

This looks clean. Is there any solder on B3?

[Jeb Jeb]

man you're good.... just doing it now.  don't know how I missed it.  Think I was keeping it raw until I'd manoeuvred in the cap at the opposite end.

well spotted!

[adydula]

Yup B3 needs some solder.... check all your joints from different angles, the lighting from different views helps to inspect the solder joints etc.

Its ok to use a different ground point other than 12, just make sure its indeed a ground. You can look on the schematic and see many components have one side on them on the ground side .....you can use anyone to your liking. Just be careful not to slip off etc and or short the probe to something else while checking the voltages.

Checking resistances this isn't that important, seeing how there is now power on. But having a good ground will aid in accurate measurements.

The question on the 119vac vs 240 vac is a good one...I assume that you have a proper step down transformer or a transformer that is wound for 240 VAC that will drop the voltage down from 240 as needed. "Someone from Bottlehead should answer this." I think the voltages will be in the same area. Even here in the states the vac can vary a few volts etch and there reading are approximate... but close. (10-15%) as stated in the manual.

For resistances you can flip the build upside down and suspend from the wood case.... for the voltage tests volts DC not AC... unless specified I had the tubes in and proped up on a table on a towel, at a angle so I could easily probe for voltages. I attach one probe to a ground point and then use the other probe to carefully touch a joint to check the voltage. Just take your time and be slow and methodical.... don't slip off a joint and short something out.

Your build looks nice and neat! When you first turn in on with the tubes in you should see the filaments glow in a few seconds.... watch for anything getting hot or smoke from the underside/component side... if after a few minutes nothing smokes etch, no fuse blow your probably ok fine and do the dc voltages checks...( this is after u check resistances of course)

Good luck!!
Alex

[Jeb Jeb]

Fantastic! - Alex - will do.  Nice explanation of your technique and all things to watch out for.   It seems like for ground it would be easiest just to clip on to the ground-buss wire.

I hope to get to it tomorrow or Sat/Sunday.   

Yes the transformer that bottlehead supplied is suitable for 240v, so i'll assume i'm looking for the same voltages as those listed, unless anyone pops in with different info in the meantime.

Cheers all and have great weekends!! 

[Chris65]

The question on the 119vac vs 240 vac is a good one...I assume that you have a proper step down transformer that will drop the voltage down from 240 as needed.

Alex, please don't comment on the products if you not familiar with them. There is no need for step-down transformers! Bottlehead supplies 240V transformers for the many parts of the world that use this voltage.

Jeb,
Just follow the manual instructions they tell all you need to know regarding the checks & safety.
Voltage readings should be as per the manual (within 10-15%), the mains voltage makes no difference (you are measuring what comes out of the transformer & in the circuit, not what goes into the transformer).
Nice build btw.

[JamieMcC]

Hi Jeb, your build looks to be coming along nicely, its good to see another UK Crack builder.

Just a little heads up as you will soon be doing your voltage checks, there used to be a misprint in the manual (not sure if its been updated in your version) but in the voltage check on page 39, Terminal 20 should read 0VDC and terminal 21 should read 206VDC

This is detailed in the manual corrections sticky at the top of the Crack forum.

http://bottlehead.com/smf/index.php?topic=657.0

Look forward to reading you are up and running
Cheers
Jamie

[Grainger49]

So... where do the UK Bottleheads gather?  I would assume in a pub, with a pint and a good sandwich. 

[Jeb Jeb]

Thanks again guys - Jamie - I will check on those manual misprints and revisions when I perform the checks this weekend. Thanks for the heads-up.

Grainger lol! - I'm yet to be fully initiated into the secret UK bottlehead meetings but yes I would assume so too!  A nice big tankard of ale and a bacon-butty at the Dog & Pheasant.   Good times

[adydula]

Sorry Chris didnt mean to ruffle any feathers....thats why I said someone from bottlehead should answer this.
Thanks your input.

Alex

[Jeb Jeb]

Alex, you've been nothing but helpful and conscientious the whole time.  I asked for your help and on that one matter you gave your best answer while also suggesting it should be clarified by Bottlehead.  It's all good.  It's fair to say I ask a LOT of questions and you've done a lot of work on that front! We're all clear now - and no harm done at all.   

Chris also - thanks for your points and compliments on my build!   Let's hope she works!

I really appreciate everyone's help on this thread.  While I'm not at home and able to work on the build i've been able to read through the tube-rolling thread too!

Cheers & let the good times roll.

Jeb.