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Old 29th Aug 2022, 4:24 pm   #1
Thatvalveguy
Triode
 
Join Date: Apr 2018
Location: Nijmegen, Netherlands (You know from that bridge)
Posts: 35
Default Magic eye tube tester

I've developed a 4x4'' PCB that furnishes all the voltages needed for a magic eye tube tester. It uses switch mode regulators so it can be run of a battery pack, which i thought was a nice capability to be able to take the unit to the radio meets.

Specs are:

Input voltage 14-19VDC

Filament voltage 2.5, 4.0 , 6.3 and 12.6V 500mA max.
Anode voltage 250V 20mA

G1 voltage sweeps automatically between 0..-17V on a 5 second interval.

One feature is the G1 supply, a 555 timer sweeps the G1 voltage of the tube between ground and circa -17V on a 5 second interval like stated above.

I'm Dutch and will be selling PCB's locally. If anyone wants to build this, feel free to contact me, i will provide Gerbers for free as i don't want to have to deal with customs forms for UK users.
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Old 29th Aug 2022, 4:34 pm   #2
Thatvalveguy
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Join Date: Apr 2018
Location: Nijmegen, Netherlands (You know from that bridge)
Posts: 35
Default Re: Magic eye tube tester

Here are some more Photo's of the prototype.

Here is a short youtube video of testing an EM80

https://www.youtube.com/shorts/j4svKDvj66w
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Old 29th Aug 2022, 8:56 pm   #3
FrankB
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Join Date: Oct 2005
Location: Olympia, Washington, USA.
Posts: 663
Default Re: Magic eye tube tester

A very useful piece of equipment. Nice job. I could sure use one here.
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Old 1st Sep 2022, 2:17 pm   #4
kan_turk
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Location: Dublin, Ireland
Posts: 396
Default Re: Magic eye tube tester

Hi
I’d like a PCB for one of these please when they’re available - no customs forms for Ireland - just put it in the post
I’d appreciate a pm at your convenience

Many thanks
John
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Old 1st Sep 2022, 6:15 pm   #5
David G4EBT
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Location: Cottingham, East Yorkshire, UK.
Posts: 5,737
Default Re: Magic eye tube tester

It's entirely a matter for the O.P. whether or not he wishes to sell PCBs to forum members outside the EU (whether the UK or other parts of the world), but it's worth explaining that VAT & Customs Duty is hardly going to be an issue for any individual, (not a registered business), who is selling goods of low value to another person overseas.

As to VAT on business transactions, I don't know what the rules are on the level at which registered businesses in countries outside the UK pay VAT, but in the UK, any business which has a turnover of less that £85,000 doesn't need to be VAT registered nor to charge VAT on goods they sell. (The downside for the business is of course that they can't claim back VAT on goods they've bought for resale).

I'm sure that quite a few forum members have bought items from Bowood Electronics, especially potentiometers, (given that they're one of the few sources who can supply 470K switched log pots for the ubiquitous Bush DAC90A volume control).

Bowood aren't VAT registered.

Quote:

We are not registered for VAT, and not required to do so by law. No extra tax is applicable for the UK. However, you are responsible for any importation and sales taxes incurred when delivery is made to your location.

End quote.

Source: https://www.bowood-electronics.co.uk/website-terms/

So if someone from outside the UK buys stuff from Bowood, no VAT is applied and it's a matter for the recipient whether any local taxes and customs duty apply.

I'm sure that many forum members have bought items over the years from other countries such as the USA and Canada - resistors and capacitors from 'Just Radios' in Canada springs to mind. All that happened with Brexit is that since 1 January 2021, the rules for the import of goods from any country outside the UK are now the same, regardless of whether the goods originate in an EU or non-EU country.

Customs Duty:

Quote:

Goods ordered from a retailer in a foreign country are exempt from customs duty if they are worth £135 or less and do not contain alcohol or tobacco. These limits also apply to gifts.

If travellers bring in goods into the UK within their £390 personal allowance they're exempt from paying VAT. Above the personal allowance, they must pay import VAT at the rate that would apply to the goods if they bought them within the UK.

Goods ordered from a retailer abroad are always liable to UK VAT, [but a forum members selling a few PCBs can hardly be regarded as a 'retailer'].

Gifts sent from an individual abroad are exempt from VAT if they are:

• worth £39 or less, and:
• contain either no alcohol, tobacco or perfume, or less than the special limits for
those goods (which vary from product to product).

End quote.

Source: https://www.instituteforgovernment.o...ers/tax-brexit

It's a topic that's been done to death in the past, though as it's been mentioned in this thread, I though some clarification might help, but I'll leave that to the judgement of the moderators.
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Old 1st Sep 2022, 9:07 pm   #6
Thatvalveguy
Triode
 
Join Date: Apr 2018
Location: Nijmegen, Netherlands (You know from that bridge)
Posts: 35
Default Re: Magic eye tube tester

David,

You have changed my mind about selling to UK forum members, PostNL seems to be decently affordable at 10 quid or so.

If anyone wants a board, i will be ordering 20-30PC sometime this weekend, taking orders through PM or public message.

I have yet to compile a BOM but that has to wait untill i can finetune some of the values of the G1 inverter rc time and filament supply voltage settings.

Cheers,
Florick
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Old 15th Oct 2022, 12:25 am   #7
Thatvalveguy
Triode
 
Join Date: Apr 2018
Location: Nijmegen, Netherlands (You know from that bridge)
Posts: 35
Default Re: Magic eye tube tester

Burning the midnight oil again.

The boards came in the mail a few weeks ago, and i have been working on supplying the Dutch forum members with populated and tested boards.

Ive figured out the component values, attached are the schematics with updated component values.

I'm doing another batch of 10 PCB's of which 6 will be available for UK/USA members if anyone wants one.

Please inquire via PM if you are interested in a board.

Price is round about €40/$40 for a populated and tested board. ex shipping.

Cheers,
Florick Wibier
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