Test gear for amateur radio tune up, repair and fettling? - Page 1
Forum section: electronics / repair

author: Chris Wilson
author_rank: Super Contributor
timestamp: February 29, 2012, 09:35:10 pm
content: Being into automotive engine management system electronics I have somebasic test gear, but I am a bit of a magpie for buying more stuffIn order to buy the *right* sort of stuff for my newly rekindledinterest in amateur radio may I ask what people recommend in the wayof test gear to set up used, repair broken, and basically fiddle with"unknown" newly acquired used ham radio stuff?I currently have a Phillips/ Fluke 2 channel 100 MHz Combi Scope (onthe fly switchable analogue to digital), a Tektronix 7633 mainframewith an assortment of plugin modules, a decent 150 MHz USB scope withtwo channels, a 2 MHz combined signal generator / frequency counter,that's very basic, but works OK. I have a small Peak semiconductortester, and the same make ESR capacitor tester. I also have a basiccheapo hand held DMM, and a couple of 4 1/2 digit bench multimeters. Forsoldering I have a Weller thermostatically controlled 20 Watt solderingstation, and a now broken Weller de-soldering station. The thermistorin the de-soldering iron is broken, and spares are no longeravailable. the vac pump in the base station works fine, which is ashame. I need to replace this ASAP, but bear in mind I am in the UK,so don't get the same range of stuff like Hakko you seem to get in theUSA.I am thinking in terms of a better signal generator, and a separatestandalone frequency counter. What sort of range do these need to betruly useful? I might want to have a go at building some 10GHz stuff,or at least having a play on that band. I guess test gear formicrowave stuff will be VERY costly, how do people manage there?I think I could do with an RF probe, and a high voltage probe forvalve stuff. Again, what sort of range do I need? 500 MHz RF probe OK?In some of my Yaesu manuals they only speak of using a VVM for RF work,but this is 1980's stuff, is there any reason not to use a fairly modern DMM instead?What other gear do people find useful? At the least I would like to beable to follow the tune up instructions for older gear myself, inhouse. I would also like to see if a receiver is "deaf" and if atransmitter is free from terrible harmonics. I guess I am getting intoexpensive spectrum analyzers there though?Thanks for reading.

author: JonnyBoats
author_rank: Regular Contributor
timestamp: March 02, 2012, 04:46:46 am
content: Whoa Chris,This isamateurradio with a strong tradition of make do, recycling old bits and making one's own gear. What you already have will do 99% of what you need to do, why not just jump in and have fun?Heck, I may be old, but I remember tuning up a transmitter into a light-bulb as a dummy load. Back then nobody had a digital meter of any kind and certainly not a high precision digital frequency meter. People were still able to communicate around the world and make lots of contacts.If as you start building specialized projects you find you really need a piece of test gear, then buy it then, not now.WA1KLI

author: sonicj
author_rank: Frequent Contributor
timestamp: March 02, 2012, 12:29:33 pm
content: Bird 43

author: vk6zgo
author_rank: Super Contributor
timestamp: March 02, 2012, 03:28:18 pm
content: The 'scopes are a good start,especially the 7633,which has a useful feature (at least my 7613 does),in that you can get access to the output of the vertical plug in,& use it as a variable gain buffer amp for such things as Frequency Counters,speaking of which,the cheap Chinese ones seem OK---I've got one.If you could find a 7L12 Spec An plug in for the 7633,you would be set!The 7L12 isn't all that marvellous,but it will do the job!A Test Load (Dummy Load) is almost essential.especially if you can get one which gives you an attenuated sample of your RF signal.You can build a lot of stuff---- An RF probe for your DMM is an easy start!Another possible project is a Dip Oscillator.Your existing Signal (function?) Generator is fairly limiting,but most really good Signal Generators are either very expensive,or very big & old!HP stuff is very good,as is Rhode & Schwarz & Boonton,but I would suggest you stick to the old Brit stuff.Marconi made some very good Generators,as well as some not so good,plus there were many other Test Equipment manufacturers in the UK back in the day.Finally,I would suggest you sign up for QRZ.com (I don't think Dave minds us promoting other forums here!).They are a nice lot,if a bit crazy,but you've got used to that onthisforum!73,VK6ZGO

author: G7PSK
author_rank: Super Contributor
timestamp: March 02, 2012, 03:45:14 pm
content: About the only thing that is a mandatory requirement for amateur radio is a means of checking your output frequency, and an absorption wave-meter will do for that.

author: Chris Wilson
author_rank: Super Contributor
timestamp: March 02, 2012, 05:50:37 pm
content: I have come upon an issue already that I don't believe I have the gear to resolve myself, at home. My newly acquired Yaesu FT-902DM transceiver seems to be displaying a different receive frequency to that which it is actually listening on. Now, I *MAY* be able to check it on a known HF frequency transmission, if such things exist, but can I re trim it to read correctly without a decent calibrated signal generator? Similarly, can I accurately check the displayed transmission frequency matches that which it is displaying? These two checks seem pretty essential with used gear, i would like to be able to at least do these checks with accuracy. I am off to Google building an RF probe, as the old HP one I am watching on Ebay is up to 50 UK pounds already. Thanks for the replies so far.

author: G7PSK
author_rank: Super Contributor
timestamp: March 02, 2012, 06:12:35 pm
content: It is a transceiver, is the frequency displayed the transmit frequency, which is different from the receive when working repeaters.It could also be that the clarifier is in use it shifts the receive up 2.5KHZ.If you don't have the manual its here: FT-101ZD-901-902 - Fox Tango Yaesu Manualswww.foxtango.kc9foz.com/FT101ZD...902/FT-101ZD-901-902.htm