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Reviews (45)
17 September 2016
Very Good Quality, Low Frequency Ferrite Rods.
These ferrite rods are very good, my tests using a 100 turn coil at 500 Khz, show the AL values between 900 to 1.100u +/- out of 20 tested.
The rods can be used for Long & Medium wave reception, either a single rod or grouped together: 8 forming a circle O/D X two lengths 280 mm 16 total; this will increase the sensitivity substantially. Also, are good enough for VLF use too, for monitoring Whistlers and Tweaks 1 to 6 Khz... any coil used LW-MW & VLF should be centered on the rod, for maximum field induction.
I highly recommend these ferrite rods.
02 April 2020
Non-Linear Systems MS-15 Mini Oscilloscope: 1970 to 80's Production USA, with Issues ?
Their are not to many on the open market these days, but some do become available on E-Bay from USA mostly; where the design and production build was ongoing, with the MS-15 single channel 15Mhz band-width MiniScope, and a two channel version; using the Alt & Chop electronic beam switching method.
NLS also produced a 30Mhz version, that in my opinion having had one, I found to have many issues, if it has not been modified by someone before you purchased it ? ! The issues are mainly due, the very cramped component design, into the same case and board area... ridiculously tight in the control sub vertical board, impossible to work on assembled in position. Also, the 30Mhz band-width was not reachable, taking into account the standard 3 dB cut-off, that was more like 8 dB roll-off under my tests anyway.
However, I would recommend the MS-15 as a neat basic small Scope, but you will need to carry out one repair, and maybe a few others; e.g. general re-alignment which is very easy if you have a sine and square wave generator. Even a Chinese Module PCB would do the job; major fault is the lead acid batteries, they dry-up and thus can't be re-charged.
This is why these Scopes are on the market, you can still get the batteries at cost form:-
Batterymart ( 2.2 Volt at 5Ah ) Hawker sealed lead acid battery.
If your lucky, this is all that's wrong with the Scope; but do expect dirty controls and the switch sliders, and some toggle's too; but with a little switch cleaner into these, the problem is resolved... no doubt it will be very dirty overall externally too. Take note: Their are some charger power supply up-dates by NLS, most are already done, as in my circuit; I decided to draw the Mod Change for my own reference, along with my two Electrolytics Mod to help anyone who wish to go down this path.
Please read on, to see why ? NLS provide in the Manual a thin yellow sheet with the changes on it, and up-dates for the testing and set-up alignment; so that's another thought to consider, effort is required to get these going.
If you only intend to use it on the bench, then don't bother with the batteries for portable use; just get a transformer. [ Secondary AC 7.5 Volt at 2 Amp # 18VA rating ], and [ two 4700uF 63Vollt Electrolytics ]… I recommend the Nover make Hi Ripple LS 30 x 40mm (Code: 054406). You install these in the area where the old batteries were; see circuit for information, and where to wire them into the rectifier circuit... reason for large capacity Electrolytics, is because the old batteries act as AC smoothing, when used at same time as the charger supply, but the AC Charger can-not provide the current required, to drive the Scope on it's own.
Be aware UK or European buyers, USA have 120 Volt Mains Supplies... thus, the power supply transformer that come with the NLS Scope, can-not be used; you need to source a 240 Volt with Secondary 12 Volt, at 500 mA would do, just for charging the NEW replacement Batteries ONLY.
My tests show the power required is around 760mA, when the regulated inverter for all the high voltages and low, is set at required 5 Volt DC adjustment.... don't be tempted to use a 12 Volt supply AC or DC high amperage for the Electrolytic Mod. The back heat sink with a single series transistor regulator, for the charging supply, will become exceedingly hot, just to dissipate 5 to 6 volts drop from the power supply transformer; thus keep to a 7.5 Volt AC transformer, once DC rectified will produced around a 2 Volt drop.
Also don't be tempted to re-adjust the Inverter for 5 Volt regulation, unless it's low or too high ! In most cases and if no one has messed with it, it's okay; but you can make voltage checks as part of the refurbishment, and is a first check before any re-alignment is undertaken.
All the tests and adjustments are set out in the Manual, when supplied with the Scope... so make sue you can have it at the same time of purchase; it's invaluable to get the Scope back into a good working condition... beyond the cute look of the Scope, it's a serious little Oscilloscope using the same CRT tube, the D5-100W by Mr. Sinclair, for his Mini TV, and the SC11A oscilloscope.
09 August 2019
The oscilloscopes intuitive operation.
The oscilloscopes intuitive operation, with easy to learn functions even if have not looked at the manual.
Each button and control has a dedicated function, there is no multi use buttons for the same control into other functions, and that makes it easy to use. Other digital handheld oscilloscopes require you to remember all the other button controls, just to drive it and use the thing, this can be confusing and cause irritation, when all you want to do, is to use it. The Owon is simplicity to operate and to enjoy, with a good size display to give clear wave-form readouts, without any fumbling around for other hidden functions.
Once you have familiarised yourself with the operation, you can explore the two assigned and adjustable read-outs, at the top of the left hand display, with your preferred most used readings.
Their is a good deal of thought put into the design of this Scope; use it as a portable handheld, or bench use; having a standard power supply switched mode type, but with a standard high quality forked DC Plug to charge the internal battery, that has a long operational life before re-charging.
The other great news is the input sensitivity is at 5mV; most of the other handhelds are at 10mV, it's surprising when the need arises, you have that extra gain, it's very useful... also, and most important; it has isolation between the Scope input and the Digital Meter Earth or signal returns... again more expensive handhelds don't have this requirement; and without separate Earths, you can cause a short between the equipment or power supplies under test, so you can keep both test probe and meter leads connected, and just switch between these two functions.
This just covers the basics of the instrument; but for the price you have a really good quality well made test equipment. I highly give my recommendation for the hobbyist and professional, for it's features with no fussing about to use the functions... it just lets you do the job.