Australia Post – The Postal Service – we use to send international packages affordability – has temporarily suspended services to the United States. This is due to the removal of de minimis exemption for low-value goods and new requirement that duties and taxes must be collected on goods prior to entering the US.
We will continue shipping to the US with Australia Post when they resume service – however the updated shipping price will reflect the additional handling and tariff payments.
In the meantime I have found an alternative shipping method using UPS Worldwide Saver which is the cheapest possible at this time (starting at 40euro) – although still more than twice the original Australia Post shipping.
Shopping within USA
Luckily we anticipated this eventuality and also arranged for LA based Perfect Circuit – the premier source for cutting edge Electronic Music, Tools, and Techniques – to distribute underscores products within the USA.
they are currently stocking most of our assembled and enclosed products in both standalone and eurorack formats. Please check them out if you are located within the US and want closer and tariff free access to our catalog!
all the circuits we design and distribute for underscores.shop are made to be diy and beginner friendly. a big part of this mission is to enable and encourage artists to engage with their own art-making tools.
often when helping people troubleshoot their circuits i am asked to recommend a digital oscilloscope they could get. also for my online class about making analog video synths on breadboard i would like to suggest some scopes that students could look into getting if they want.
in this post i will outline some of the features of a digital oscilloscope that make it useful for building and testing diy video circuits and then suggest a few options across a range of prices and feature sets.
main features to look for
the bandwidth – ie the the range of frequencies that it can accurately measure (this is rated in Hertz)
whether it has trigger modes – most modern scopes do
number of analog inputs
does it include a signal generator ?
does it include a multi-meter ?
what form-factor would suit your needs ?
my quick thoughts on these in general:
composite video uses around 4-5Mhz and vga @ 640*480 needs around 14Mhz so more than this is ideal for a scope to inspect video signals (especially hd ones) – however in practice i would rarely need to see all the details of the subcarrier or every pixel so you could definitely get away with less
triggering on the rising/falling edges is often essential to get a stable look at video signals – would recommend checking your scope can do this.
having two analog inputs can be very useful although this often increases cost as well – if you have the budget definitely go for this but don’t stress if not
signal generators can be useful for testing circuits and are fun to play with but not essential
a multi-meter is pretty essential for working with electronics – if you dont have one already then a combined meter + scope could be a good option for you
i like the small and portable kinds that run on rechargeable batteries but i also have a larger desktop scope that i mainly use.
ZEEWEII DSO154Pro 18M – cheapest option i recommend
i got one of these ZEEWEII DSO154Pro 18M from aliexpress for around 25 euros and was pretty impressed with the results – learning the interface is a bit clunky on lots of these machines but once you get the hang of it seems like a great first choice:
claims 18Mhz of bandwidth – at least in my tests inspecting a color-burst at 500ns divs it looked fine
triggers worked as i would expect
only has one input to the scope
has a built-in signal generator – this seemed pretty good:
i like that you can use it to generate really slow (0.1Hz) oscillations
would be nice if the vpp was adjustable but it is not
does not include multi-meter – which is fine for me i already had one
is very small form-factor – comes with rechargeable battery that lasts long enough
i have not tested these myself but have seen them recommended as good entry level-scopes online. you can get ZOYI ZT-703S on aliexpress for around 70 euros – so more than twice the price of the mini-ZEEWEII however:
50Mhz of bandwidth claimed
2 channels of analog input – very helpful for comparing signals etc
built in function generator (with adjustable vpp!) and a multi-meter in a nice portable form-factor
seems like quite a good option if you want 2 channels / need a multimeter anyway… they also have a 1 channel version the ZOYI ZT-702S for 50 euros however this only has 10Mhz bandwidth which is a little on the slower side – could be ok tho…
OWON HDS242 – a solid portable 2ch scope + multi-tool for a bit more
i picked up one of these when i needed a portable scope / multi-tool for some installations i was doing away from my bench. you can get the OWON HDS242 on aliexpress for around 110 euros (+20 euros if you want the optional signal generator also) – it is well made and easy to use. runs at 40Mhz and im sure is better quality than the ZOYI ZT-703S… however im not sure it is worth the almost twice the price with similar specs… especially for my uses as a secondary one – i might sell this and just use the ZEEWEII DSO154Pro for when im away from my bench going forward
a Rigol DS1054Z or similar second-hand ?
these Rigol DS1054Z are professional machines (with lots of features i never touch!) and mine has served me well for many years and will for many more i hope. i think they retail at around 440 euros but i got one less than half that price from a closing mens shed. (plus theres a well documented firmware hack to unlock extra bandwidth!) so always check out the second-hand market before buying anything new!
FG-100 – a cheap signal generator
its not a scope but if you want a cheap signal generator thats not attached to your scope i found these FG-100 DDS Function Generators on aliexpress for around 15 euros to be a good way to add signals to your circuits.
the interface to set the frequency value is awful but i really like how it has a knob for variable amplitude (up to 10vpp) plus another little knob for dc offset!
things have seemed a bit quiet over on the research side of underscores lately – and not for lack of a (growing) backlog of interesting diy projects that we want to release !
introducing Polyphase Portal
its partly because i’ve been putting more time recently into an exciting side-quest: polyphaseportal.xyz – an educational focused online space and media-art collective
together with some friends, organizers and educators we are creating a new online space to host educational programmes such as talks, live-streams, workshops and multi-week courses. taking encouragement from the success of PHASE SPACE in NYC we are aiming to facilitate accessible non-hierarchical learning over open and ethical technology – find out more at polyphaseportal.xyz & join the polyphase mailing list to stay in the loop!
which brings me to the next announcement – im teaching an online course !
you can read more about it and join the class wait-list on the Polyphase Portal here
no prior experience or specialized equipment is needed – this course will focus on the practical side of building modules on breadboards – you will receive a course materials kit in the mail that includes all the parts and components we will use.
the course makes use of this custom vga_breadboard_module pcb to interface between vga signals and the breadboard.
one day i hope to make this circuit and the corresponding course material kits + module designs available in the shop as stand-alone products you can build and learn from independent of this online course – but for now if you are interested you should sign up – it will be fun!
