Re: The "Sussex" Homebrew Valve Tester.
 

Hi,
the seller is housings24

The item is Console Housing Large Dashboard Empty Enclosure

I have just logged into the UK Ebay site and searched for the seller and found the above housing.

Hope this helps.

Re: The "Sussex" Homebrew Valve Tester.
 

That search works for me, I just copied & pasted.....

Re: The "Sussex" Homebrew Valve Tester.
 

You have to use https://www.ebay.de/
https://www.ebay.de/sch/i.html?_osac...88221&_sacat=0

Re: The "Sussex" Homebrew Valve Tester.
 

Hi!

Altho' I'm still trying to work out what size and shape of case to build my new Sussex V.T. in, one thing I can definitely suggest to others is wiring!

For wiring the valve holder tags together in parallel, I recommend two lengths together of 1/0.6 mm single–core connecting wire, i.e., two pieces of wire connecting tag 1 to tag 1 etc.

You can buy 11 colour packs of 1/0.6 and one 5m pack of 11 colours will cover all the inter–valve holder wiring, and I suggest identification as per the standard colour code, pins 1 brown, pins 2 red, pins 3 orange, and so on!

For wiring between the switches, valve holders, PCBs, displays, etc., I recommend 5m of 18 core Dec Stan 61 – 12 cable, size designation "16–2–18C" – this is 0.5mm² cable rated 3A core at 1000VDC/600V RMS a.c., 18 cores – this will give you ten standard Electronics colours, plus pink & turquoise (aqua) and six tracer colours – this can be bought in 5m lengths!

Unfortunately I've found Ed Dinning isn't consistent with wire sizes, types and colours with his transformers, and I strongly advise the leads from each secondary of the Sussex's Mains Transformer are separately enclosed in p.v.c. sleeving – I've bought three transformers from him and some of them have very thin connecting wire!

Chris Williams

PS!

I will produce suggested circuit and wiring diagrams for Martin's PCBs during the next month when I can afford a length of 16–2–18C cable!

For connecting the Meter Displays I recommend a kit of XH connectors and contacts is bought in order to use better quality connecting wire than the odd yakky bits the Chinese supply with the meters!

Chris Williams

Re: The "Sussex" Homebrew Valve Tester.
 

Hi!

Sorry to be a pain in the proverbial, but that seller of the Blue Console case says he won't post to the UK!

Can anyone find me anything similar that I can order please – I've spent two hours constantly getting "no results found" and I'm getting fed up of it!

Chris Williams

Re: The "Sussex" Homebrew Valve Tester.
 

I used the Deltron 519-0920, RS Components 232-774.
Ideally it needs to be slightly larger as it is a bit of a 'shoe horning' to get everything in but do-able. Built with the original circuit boards so not sure of the room available with the new latest boards, also I note you need more space for the extra valve holders you want to fit. :'(

Re: The "Sussex" Homebrew Valve Tester.
 

Hammond Mfg has a range of boxes in different heights/widths which I think is identical to the Deltron ones here: http://www.hammondmfg.com/dwg16Steel.htm

/Martin

Re: The "Sussex" Homebrew Valve Tester.
 

Hi Gents, note that connecting wire on the transformers is related to that particular winding's current capacity.
It would not be good to use 1mm^2 wire on a bias winding carrying 5mA

Ed

Re: The "Sussex" Homebrew Valve Tester.
 

Hi !

For a very long time i have been thinking of building my own version of the Sussex, using parts that i have at hand - for years. The worst part is in this project as always - the main transformer. On all other than the heater voltages i have transformers for the job. But, maybe a stupid question, why not use DC for supplying the heater voltage? Supplying DC would be a very easy way out, at least in the range 2-24V at a couple of amps at the most. I think i have browsed all messages over a couple of years in this thread and found nothing - i still may have missed them...
Erik/Norway

Re: The "Sussex" Homebrew Valve Tester.
 

I am also building my own version of the Sussex using several transformers to get the supplies I need.
For the heaters I am indeed using DC. I am using a chinese buck converter to allow me to set the heater voltage at whatever voltage I want using a 10 turn pot and a digital panel meter.


Peter

Re: The "Sussex" Homebrew Valve Tester.
 

I built my own valve tester, not the Sussex and used a LM317 variable 0-30v PSU using two TIP3055's as series pass trannies, this gets 0-30 @ 3A. I did rig it so it did fixed values too, IE 5, 6.3, 12.6v etc but found several valves tested exceeded their heater max voltage. The only problem though might be testing some directly heated filament type valves especially rectifiers, something to bear in mind.

Andy.

Re: The "Sussex" Homebrew Valve Tester.
 

If you want an AC heater that is variable I can recommend using a small Variac in front of a transformer with the maximum output voltage/current that you need, or the other way around.

You'll have to calculate the power necessary for the Variac and transformer and add some extra power to make sure that it works under full load. If you want this to work with regulation there are Constant Voltage Variacs that use a small motor to control the Variac by measuring the output voltage - with necessary scaling of the voltage in the feedback circuit you can get it to monitor the output voltage from the transformer too, not just the output voltage of the Variac.

There are also low-voltage Variacs which require a transformer in front of it to work, like the ones from Thalheimer Transformatorenwerke sold by Conrad, the KSS103 (42V@2.5A) and KSS105 (60V@5A) are just fine to use after a suitable transformer. Sizes and data here: https://ttw.world/index.php/ess-sing...tion-mode.html click the arrow on the bottom line (Input voltage 42 V; 60 V and 230 V; output 0 up to 42 V/ 60 V and 250 V) to see data, click the Variac number and then the arrow to see the sizes (70*55mm and 94.5*58mm).

It is not cheap nor is it small but it works very well whichever of these solutions you go for.

I have an isolated Variac for school use which works with the full mains voltage which I have used in conjunction with a transformer to get low voltages and high currents and it works like a charm.

/Martin

Re: The "Sussex" Homebrew Valve Tester.
 

Just a quick note in case this is of use to prospective Sussex builders. A couple of years ago, when I first considered building Mike Rowe's excellent design I sourced the meters from Asia. These are blue LED (not LCD) types with an explicitly stated isolated power requirement of 5V DC, so not universal AC/DC as some other meters.

Now I have started building the Sussex I decided to test the meters, all seems fine although the linearity of the 200mV AC meter leaves a lot to be desired.

However, and this is what may be of significance for budding constructors, being LED types they draw between 40 and 80mA each depending on the number of segments lit. This seemed rather high to me so I checked the other meters with the same results. I wasn't sure whether the 4 6V meter windings on Ed's transformer could cope with this current demand, so I contacted him and was informed that the meter windings and lead out wires are the same, so the current carrying capabilities should be no problem although the windings were not specified for this level of current. The extra demand on the primary winding should not be a problem as we are talking about a couple of Watts and the demand on other windings will be intermittent. (Ed, please correct me if I have got this wrong).

If you are using the now more common LCD meters, I would imagine that you will not have this problem.

Re: The "Sussex" Homebrew Valve Tester.
 

Hi Gents, as per Eddie's post; the meter windings are wound with stranded PVC insulated wire. This will carry the current required and will also give high isolation between supplies, but will cause additional heating due to the increased pri current. It will also cause additional droop in output voltages due to transformer regulation.
With 240v in on the 240v tap these windings typically give 7.5V out on no load; rectified this will give over 9v DC on no load, but possibly closer to 6v with a 40mA load. It will depend on the rectifier circuit used.

On Eddie's transformer I provided an additional meter winding as is available on request.

Note that variations are available on these transformers as long as the consumption remains within design limits. Note that a much bigger transformer is needed if you need to burn in power valves, as well as increased heatsinks on the regulators.

Ed

Re: The "Sussex" Homebrew Valve Tester.
 

Hi Everyone,

I have just completed the Sussex valve tester and because it is a cut down version on the original Sussex I've called it 'The Sussex Junior' - I hope I'm not busting any rules on the forum and it's OK to call this one 'Junior' and to post it here as part of the Sussex legacy.

I wanted to build a well designed tester but for it not to be as complicated as the original Sussex so I cut down on a few things but still leaving a very capable tester that can still do almost everything the Sussex can but all be it, in part 'manually'.

Electrically the HT & Screen circuits are the same and the grid circuit too but with a zener clamping the voltage to -20V as my meter from a far Eastern country only goes down to 20V.

What is different:
1) There is no gm oscillator or meter.
2) There are no dials but instead banana plugs for selecting different combinations of valve pins
3) The continuity test is done manually and there is a LED for this purpose.
4) I have taken all relays out.
5) There no other voltages for the heater apart from 6.3V.

Points worth mentioning:
1) I discarded the gm function as I can vary the grid voltage by half a Volt above and bellow the spec grid Voltage which will give me the same result as with a gm meter. I also had a small project box and could not fit the third meter in so went without.
2) I decided to use banana plugs as I did not have any room for dials, this was also simpler too construct.
3) I didn't want the complication of the continuity tester and also wanted to test every possible pin combination so I added a LED and it is checked manually.
4) As I didn't have the continuity function I took all relays out even the HT one and used a suitable switch instead for the HT.
5) As most of the valves I test are 6.3V I left it at just that. I have a bench supply which would give me all other voltages as required especially for the likes of UL41 etc... 100mA heater valves.

The 'Junior' might appeal to someone who has either a small project box, wants a smaller form or just wants a simpler to build tester but with the same proven HT, Screen and Grid design and is not too worried about doing some manual checks.

I have included some pictures testing a 6L6 and also using the heater voltage and the LED for continuity/shorts.

I'd like to thank Ed Dinning for winding the transformer, great work Ed and works well!

Happy building,
Berni

Re: The "Sussex" Homebrew Valve Tester.
 

Nice one Berni, looks very neat. A higher power version of this would do for those who want to "burn in " power valves

Ed

Re: The "Sussex" Homebrew Valve Tester.
 

Thank you Ed.

It would better if I had letraset or the skill to do nice lettering.

I forgot to mention that I used a veroboard and have tucked away the other heater wires incase I need them for the future as I thought I would use them in this project.

For the grid pot I have used a multiturn device and this has really improved the adjustability of the grid Volts when testing something like an ecc83.
The 20V meter reads two decimal places which is nice when fine adjusting with the multiturn pot.

I've made "Valve Spec Strips" which can be put by the pin terminals, which makes the wiring easy and you can read off the parameters quickly.

Berni

Re: The "Sussex" Homebrew Valve Tester.
 

I have the control panel part of the 2 panel AVO tester and also made up a patch panel to connect to the correct pins on the valve bases. (I have since got a full 2 panel AVO but that's another story.

To make connecting easier I converted the AVO valve switch setting manual to Excel and used the Vlookup function to add the valve pin connection by name (A,A1,G.C etc.). see screen shot below.

Its too big to post as an Excel file so I have zipped it.

Peter

Re: The "Sussex" Homebrew Valve Tester.
 

Electronpusher0,

Thank you for the file, it'll be very useful!

Berni

Re: The "Sussex" Homebrew Valve Tester.
 

Hi all,
here a couple of photos of my current project. It is still very much work in progress, but I have got all chassis bashing out of the way (I'm not the world's best metal worker). Although the aluminium panels were not cheap, I am pleased with the finish, I could never have achieved the same precision with the tools available here.

I still have to populate the PCB and connect it all up, however the valveholders and pin switches have all been wired up before installing, but still some way to go.

Sorry about the mediocre quality of the photos, but I hope you can see what I've done so far.

I will keep you posted on the outcome.

Re: The "Sussex" Homebrew Valve Tester.
 

That looks really good! I'm planning to have the same amount of meters as you.
How did you make the labels? And where did you get the enclosure?

Re: The "Sussex" Homebrew Valve Tester.
 

Hi, thanks for the kind words.

I got the housing off Ebay in Germany. See posts 1551 ff on this thread for more details.

I made cut outs, slightly larger than necessary on the case itself and had the two aluminium panels made by a german firm called Schaeffer in Berlin. On their website they supply a free software program to create the layout required, this includes text facilities for either printing or engraving. The software will also quote the price, I paid approx. 90 Euros for the larger panel und 47 Euros for the smaller. They took about 10 days to arrive and saved much work and as I mentioned above I would not have been able to make them to the same exact measurements.

PS just seen you are also in Germany, so shouldn't be any problem for you :-)

Re: The "Sussex" Homebrew Valve Tester.
 

Thanks for the tip! I will check it out.

Re: The "Sussex" Homebrew Valve Tester.
 

My Sussex shown in post 1020 has an aluminium panel with the cutouts and the printing was done on a sheet of A3 paper glued to the panel with a clear sticky plastic protection sheet applied. Has been used many time now and no sign of wear. Cheap to print and changes can easily be made prior to the final version which was applied.

Re: The "Sussex" Homebrew Valve Tester.
 

Looks very nice as well but a bit difficult to see in detail. Do you have a more high-res picture?

Re: The "Sussex" Homebrew Valve Tester.
 

The forum software reduces the image file but I think you can click on the thumbnail then the image and it should enlarge.

Re: The "Sussex" Homebrew Valve Tester.
 

vidjoman - I thought about the paper, transparent plastic, however I have found in the past that I either get annoying air bubbles in the plastic or the edges start to curl up and become loose.

Another advantage is that my cut outs didn't need to be precise, the underlying material being 1,5mm steel which is not that easy for me to work with. The CNC machined aluminium panels provide the necessary precision.

sven - I'll try to get a better image, possibly as a pdf.

Re: The "Sussex" Homebrew Valve Tester.
 

Hi Berni - I am very interested in your 'Junior' - I started out on this project some years ago and now with the COVID19 lockdown it seems as good a time as any to get back into it! Have you a slimmed down circuit diagram you could share? best regards and stay safe, Ramon

Re: The "Sussex" Homebrew Valve Tester.
 

Hi all,

I started to gather the components for Sussex almost 1 year ago and now finally i completed it.
For case i used a suitcase, available here in a DIY store, from china, and is made from pressed cardboard with a layer of thin aluminum (i think).
I manually winded the secondary in the transformer which was taken from an loudspeaker enclosure acquired from local flea market.
The valve sockets were acquired from the same local flea market.
To my shame, i lost a few hours figuring out the connections on board, until i found that the silkscreen contains the necessary info :)

Re: The "Sussex" Homebrew Valve Tester.
 

Hi all,

I needed some additional vacuum tube sockets to complete the Sussex and as they were not available at a reasonable price here in Romania I designed and 3D printed them.

Here is the link to FreeCAD files if anyone needs them:-

Vacuum Tube Sockets

Re: The "Sussex" Homebrew Valve Tester.
 

Hi Ramon,

Sorry for the delay, I occasionally pop in here to have a look.

Regarding the circuit, I can dig up the diagram and post it here, not sure if I will be going off topic. If I am then we can get in touch via PM or email.

Basically I bought the transformer off Ed who is on this forum and in this thread, he makes the transformer for the Sussex and I highly recommend buying this from him as I searched hi ans low to find something similar and could not. You can use other transformers but you will end up perhaps with a few to do the whole job, good if you have space, I didn't.

Circuit - The Junior has the transformer and both circuits for HT and Screen, the grid circuit but no oscillator. I do not have any relays and use a switch in the HT to turn on and off the HT. I also do not use all the heater voltage outputs as I did not have space to put extra banana plugs but you might be able to. I use only 6.3v and 5v as these are the main valve heater supplies I use, so it is specific to my requirements but you could drill a few more holes and have the lot.

I'll try and draw something up and post it.

All the best,
Berni

Re: The "Sussex" Homebrew Valve Tester.
 

Hi there. I'm very interested in this project.
I was wondering if there is a kit.
The other problem is I live in Thailand.
De HS0ZLQ /G0MIH

Re: The "Sussex" Homebrew Valve Tester.
 

I am planning on using an external PSU for heater supplies, and I have small PCB transformers for the meter supplies.
Can I have a single supply for bias, screen and plate? I am considering a 200 VA torpid, with a 33-0-33 secondary, with a voltage quadrupler.

Re: The "Sussex" Homebrew Valve Tester.
 

Hi everyone.

I bought last year the PCB's (one main and four small for selector switches).
I think it is the last version, on the back says: Sussex valve tester by Martin Forsberg Sweden
I am very confused with the component list, no correct BOM found,
Does anyone can help?
I'll appreciated
Best regards
Alex

Re: The "Sussex" Homebrew Valve Tester.
 

Hi Alex, and welcome!

Just look back in this thread for member "Dekatron" - the member's name in this case not the number of posts indication, which is also Dekatron for some people. This is Martin Forsberg's user name.

Click on his name and you'll get a drop-down menu, and from here you can send him a personal message. The forum will send him an alert email if he has the facility turned on.

You could also click "find all posts by...." and then scroll through that list and you'll likely find one with the BOM attached.

David

Re: The "Sussex" Homebrew Valve Tester.
 

In post #1477 you'll find most files for the CB, including a schematic with all component values bythe components: https://www.vintage-radio.net/forum/...postcount=1477

In this post I've included a PDF-file with just the BOM taken from the schematic in post #1477. Now, I've never built a Sussex myself so I can't say if it is correct or not but it was exported from the Designspark file.

Forum user G8UWM-MildMartin sold the PCBs, maybe he is still selling them, and he should have a BOM too.

Re: The "Sussex" Homebrew Valve Tester.
 

Thanks, Martin

David

Re: The "Sussex" Homebrew Valve Tester.
 

Thanks a lot! Now thinks are more easy..
I have one more question, I've noticed there are same parts in main PCB and selector PCBs, for example C1, R3, R5, R6, R7...
Should I use both or only one of them?
May be silly question, but I think is better asking
Best Regards
Alex

Re: The "Sussex" Homebrew Valve Tester.
 

The BOM in post #1586 is only for the main PCB, there are no BOM files for the switches, all component values for the switches are in the files in post #1477 in the circuit diagrams.

Re: The "Sussex" Homebrew Valve Tester.
 

Thanks Martin, I've noticed that after posting.
Best regards
Alex

Re: The "Sussex" Homebrew Valve Tester.
 

The reason why I didn't adjust the component numbering was due to the version of Designspark that I made these PCBs on didn't work with multi-sheet schematics with component numbering streching over deiffernt sheets. I discussed it with some people here on the forum and decided to keep as much as possible original when it cam to numbering, but the switch PCBs were also added after the main PCB was finished.

In the future anyone who wants can convert them to a modern version of Designspark if they want and then change the numbering while using multi-page schematics that are connected.

Re: The "Sussex" Homebrew Valve Tester.
 

Hi!

I've been thinking about the construction of this unit, and the fact that the power input and the sense input of the original LCD panel meters shares one connector suggests to me that terminating the four 6V mains transformer meter supply secondaries and the meter connections in in a simple "junction box" connector PCB will allow simple 4 way leads and plugs to run up to each meter module, with additional 2 way leads and plugs to carry the meter inputs to the main Valve Tester PCB – the design I suggest is intended for Martin's PCB that carries 2–pin connections for the meter output connections!

I thought of this as a way of making the interconnecting wiring a little simpler and neater, that's all!

I'll get this drawn up & design files with Gerber's posted in a day or two!

Chris Williams

Re: The "Sussex" Homebrew Valve Tester.
 

I think I may be reading this incorrectly, but please bear in mind that the supplies to the meters must be independent, as stated on P14 of the manual.

I might well get around to some construction of mine, but there is so much on the "round-to-it" pile that I can't make any predictions. Perhaps lockdown for a few more years? (only joking!).

Colin.

Re: The "Sussex" Homebrew Valve Tester.
 

Hi!
I have built the tester and I was able to correctly test 12AX7s (dual triode).
However, all tests with power tubes (tetrodes and pentodes) presented weird results that I'm questioning (especially because some of these tubes are being used in amps with no problems at all; no identifiable noise, pops or anything).
None of them present any shorts.
When in test mode, plate current and transconductance numbers increase gradually (but faster than when measuring triodes) up to around spec numbers and then grow faster. Current stays quite unstable, varying between 1.5x to 3x spec plate current.
Transconductance also gets unstable, varying from 5x to 10x spec transconductance.
Tubes warm up really fast and I can assume they're hotter than they should (no red plating, though. I didn't wait too long, however, hoping I don't blow these working tubes).
All of them fail GAS test (numbers very different from zero). In most cases, display shows 1 (above meter range).
I have tested 4 different (but old) EL84s. These are quite old, so I expected something wrong, but more on the low current/transconductance side, even though I use two of them in an amp.
2 different KT77s. JJs, were working fine until about 5 years ago.
1 6L6gc (JJ).

A friend had tested my tester and said it was working fine.
Would anyone have a guess about what could have happened and what kind of issue I should try to look for to troubleshoot? (and how to check)

I would guess it's something related to the screen part of the circuit (since 12ax7s are testing fine), maybe a zener that is not limiting what it should limit...

any help is much appreciated.
Thank you!

Re: The "Sussex" Homebrew Valve Tester.
 

Hi, try checking the heater voltage applied to the valve is correct with a good meter. This can vary a lot if your mains is also varying. The transformer I designed for the Sussex has multiple primary taps to get over this problem, but will not compensate if the voltage is varying rapidly, or if the mains waveform is poor (not sinusoidal) as can happen with heavily loaded power systems.
For accurate results a true RMS meter is needed.

Ed

Re: The "Sussex" Homebrew Valve Tester.
 

Did you use ferrite beads on all wiring for the valve sockets?

Have you tested with a grid stopper resistor?

It could be that the valve under test is oscillating which can result in strange behaviour when measured, it can even affect the tube tester so that it doesn't regulate the voltages correctly and even affect the oscillator used to drive the grid.

Re: The "Sussex" Homebrew Valve Tester.
 

I second that, whilst testing the valve and getting strange results, try placing your hand around the glass envelope. If it causes changes then the valve is oscillating. In the past I have used a few turns of Grounded wire wrapped around the envelope and moved this loop up and down to stop the oscillation. This is only a problem I find with valves like EL34 and some KT88's. I may try fitting a grid stopper in just the octal base for these valves and hope that other valves tested in the socket are not affected by the resistor.
Les

Re: The "Sussex" Homebrew Valve Tester.
 

All voltages (including heater) are correct (at least when no tubes loaded). I'll test voltages on other socket with tube loaded. I assume I should always measure voltages in "Test" mode.

Re: The "Sussex" Homebrew Valve Tester.
 

Hi,

No, I'm not using ferrite beads.
Your hypothesis makes sense to me. How can I use a grid stopper resistor? Just in series with the grid connector or should there be a grid leak to ground?
I assume the grid stopper resistor value would be tube-specific. So, how to determine the value for each?

Re: The "Sussex" Homebrew Valve Tester.
 

I'd start with using ferrites on all wires, it has been discussed here in this thread and it was AVO who patented the meathod in their valve testers a long time ago.

Grid stopper resistor comes second after ferrites, from a few kiloohms up to tens of kiloohms is usually enough and in series with the grid wire close to the socket.