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oldschool@tubes.com: Mar 14 12:45AM -0500 Looking on the web, I have found numerous suggestions and no definite answer.   To make a shielded test lead for use on a RF device, such as a Signal generator, Oscilloscope, or other, I have seen recommendations for TV coax (RG59), CB/Ham antenna wire (RG58) and microphone cable. Which is best?   I know that the TV cable is stiff, with that solid wire in the center, so that would not be the ideal cable to use. It's been years since I used the CB/Ham cable. I know that stuff is stoffer too, but maybe not as bad. As far as handling and softness, I know the Mic cable is probably the best, but I read that it's probably the least desireable because of impedance issues.   So what is normally used?     BTW: * I might be wrong on those RG numbers. I'm just going on my failing memory.

Look165 <look165@numericable.fr>: Mar 14 08:33AM +0100 For RF, the best is the cheapest !   A tube of aspirine for instance with a hole on the top for the lead.   I use this for my scope probe, it is perfect.

gregz <zekor@comcast.net>: Mar 14 08:40AM > BTW: > * I might be wrong on those RG numbers. I'm just going on my failing > memory.   I have used the stranded coax, RG58AU, RG174,   Greg

Ralph Mowery <rmowery28146@earthlink.net>: Mar 14 10:03AM -0400 In article <060fcchp00vc2d7rv8nn3ic05qa9iia1me@4ax.com>, oldschool@tubes.com says...   > BTW: > * I might be wrong on those RG numbers. I'm just going on my failing > memory.   All depends on the type of testing. For RF I usually use some rg-400. It is slightly less than 1/4 of an inch in diameter ( same size as the rg-58) That is double shielded silver plated and a stranded center wire. But that is because I am often doing duplex work and need the isolation of the double shielding. RG 58 is fine if you do not need the extra shielding. Just get the kind with the stranded center conductor.   Usualy rg 174 for light weight leads. It is about 1/8 of an inch in diameter. I am not sure of the number but there is a teflon and silver cable made in the same size.   All that is for a 50 ohm system or audio work.   Most scopes will use a probe with a 10/1 on it. You can get them from the China places off ebay for about 15 to 20 dollars per pair. I bought a set and compaired them to some HP probes rated at 100 MHz and they seem to be about the same. Not sure how long they will last, but at that price should be good for a while if not mistreated. Without the 10/1 probe you will often load down a circuit with the scope leads. The cable will have about 30 pf of capacitance per foot. I am thinking the scope only has about a 1 meg ohm of impedance without the 10/1 probe.

Jeff Liebermann <jeffl@cruzio.com>: Mar 14 09:19AM -0700 >generator, Oscilloscope, or other, I have seen recommendations for TV >coax (RG59), CB/Ham antenna wire (RG58) and microphone cable. Which is >best? (...) >So what is normally used?   I use RG-58c/u for 50 ohm test leads. The stranded center wire is more flexible than the rather stiff RG-58a/u.   For 75 ohm RF, I use RG-6/u double shielded CATV cable with F connectors on both ends. If I need to plug into test equipment, I have female F to Male BNC adapater.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

dimic <dimic.130da2c8@diybanter.com>: Mar 14 01:52PM +0100 I have philips PM5165 sweep generator with frequency stability problem. After it is turned on, it need time to establish constant frequency.         -- dimic

amdx <nojunk@knology.net>: Mar 13 01:43PM -0500 > I've been looking into buying an Audio Generator (Sine and Square Wave).   If you have any interest in building one, look up the XR2206. It is an old but a pretty cool chip. It will do many functions up to 1 Mhz. Lots of info available, I even see one Arduino controlled unit.   Mikek     --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

amdx <nojunk@knology.net>: Mar 13 02:01PM -0500 On 3/13/2017 1:43 PM, amdx wrote: > old but a pretty cool chip. It will do many functions up to 1 Mhz. > Lots of info available, I even see one Arduino controlled unit.   > Mikek   Ebay has a XR2206 kit for $9 with a case.   > http://www.ebay.com/itm/171999013818   Here's a 4 part video of assembly, part 4, you can find 1,2 and 3.   > https://www.youtube.com/watch?annotation_id=annotation_1309899397&feature=iv&src_vid=n9sbUxz92uM&v=sKRbb0rJzOE   Mikek         --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

oldschool@tubes.com: Mar 13 02:23PM -0500 On Mon, 13 Mar 2017 09:27:50 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote:   >You're doing this backwards.   >Note: You can use a PC sound card as a swept audio source and >function generator:     Thanks to all who replied. I read that WIkipedia article, which explained what these things are, (even though that article was like reading a legal manual).   When I descibed this thing, I actually had looked at several of them from China, which all looked identical. One of them said it goes to 8mhz, using the BNC connector labeled HS. Either way, that dont much matter, since I have my old Eico tube signal generator, for RF use.   I probably am doing this backward, but I really was not looking for something like this. I was looking for an old tube based audio generator, such as the Eico 377. But you know how ebay tends to show a hundred other things that are similar, and these function generators came up. I had to spend a good amount of time reading about them, since I was not familiar with them at all.   I am somewhat aware about using a computer with software to act as a signal generator, oscilloscope, etc. I'll have to read up more on all of that, but in all honesty, I would not even consider connecting my laptop computer to anything other than and audio input connector on a tube amp. I said I also want something for testing interstage circuits, and that means applying a test probe to a spot inside a device that may have 400 or more volts on it. Even with a capacitor and other protection, there is no way in hell that I am gonna risk destroying an expensive and fragile laptop computer. And while I have several spare deshtop machines, I do not keep them in my shop. I dont have the space and I dont want to be distracted by computers when I'm soldering. If I do take any computers in my shop, it's my laptop, and I only do so to view a schematic on the screen.   In all honesty, what I really want to buy is still an old tube type audio generator. That is what was made for the gear that I mostly work on, and that old tube stuff is built to hold up, as well as being easy to repair if it breaks. The problem is that this old tube stuff is selling for way too much money on ebay. Heck, some of those old Eico 377's are asking as much just for shipping as I am willing to pay for the whole thing, and one of them looks like it went thru a war, and is being sold For PARTS.....   Which reminds me, does anyone know of other sources for buying that old tube test gear, besides ebay? There must be other sources.... It's NOT Amazon, I checked, even though I have never cared much for Amazon. They just dont sell old stuff like this.   I might still buy one of these DDS devices, just for the heck of it. For $15, I'm sure I'll have some fun with it..... I actually found some of them (identical( located in the U.S. for $17. (I dont buy from China because it takes too long to get the stuff). I also found another one in the US that comes with the matching wall wart for $23. (Which I'd probably buy, or I will just end up having to spend another $5 or more to order that wart separately.   So, the bottom line is that I may buy one of these DDS devices, but I will still continue to look for the tube type audio generator which is what I really want in my shop for testing my old tube gear.

oldschool@tubes.com: Mar 13 02:33PM -0500 >an old but a pretty cool chip. It will do many functions up to 1 Mhz. > Lots of info available, I even see one Arduino controlled unit.   > Mikek   I suppose I could look this up, but I have other things to do at the moment, so I am just gonna ask.... What is Arduino? I'm Old School, so I dont know much about all this new technology.

"pfjw@aol.com" <pfjw@aol.com>: Mar 13 12:33PM -0700 Hamfests. Radio Shows. Local radio clubs (there is at least one, often several in every state). Craig's List. Put up a want-ad on Craig's List. Yard and Garage sales - especially in older neighborhoods. TV Repair shops - Amazing what some of them have sitting in the back room - *IF* one still exists in your area.   And if you are anywhere near/around Kutztown, PA in May, the Kutztown Radio Show will have what you need at reasonable prices.   Peter Wieck Melrose Park, PA

amdx <nojunk@knology.net>: Mar 13 02:51PM -0500 > I suppose I could look this up, but I have other things to do at the > moment, so I am just gonna ask.... What is Arduino? > I'm Old School, so I dont know much about all this new technology.   Skip it, just look at this if it is of interest go look at the video.   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

oldschool@tubes.com: Mar 13 03:03PM -0500 On Mon, 13 Mar 2017 12:33:27 -0700 (PDT), "pfjw@aol.com" <pfjw@aol.com> wrote:   >Show will have what you need at reasonable prices.   >Peter Wieck >Melrose Park, PA   Where I live, in a very rural area, there is really no such thing as Hamfests unless I drive hundreds of miles. There is one in August, which is 60 miles from here. I plan to go to that, but that's months away.   The last TV shop closed up about 10 years ago, around here. Even Radio Shack (25 miles away), is now a small corner in an appliance store.   I am an avid yard/garage sale addict. If I see one, I MUST stop and see what they have.... <LOL> But electronic test gear is not something I have ever found. Around here, I'm more likely to find farm machinery and all the usual household junk.   No, I am NOT near PA.   I will look at Craigslist though. I have bought from CL quite a few times, but I never put a want-ad on it. That is a good thought.   Dont they have any "Ham Fests" (Or similar) online?   Because of where I live, I have to buy all my electronics parts and stuff online. There just is no other source nearby. (except for that very minimal Radio Shack store).   Now, if any of you guys are looking for farm tractors, and machinery, cattle, horses, or anything like that, I can help. (Just dont ask me to ship them) :)

Ralph Mowery <rmowery28146@earthlink.net>: Mar 13 04:28PM -0400 In article <74qdcctjlg47haiip530nl5npshooo59q1@4ax.com>, oldschool@tubes.com says... > 377's are asking as much just for shipping as I am willing to pay for > the whole thing, and one of them looks like it went thru a war, and is > being sold For PARTS.....   Back when it was made (probably around 1960 to 1980) that was the best that could be had for a reasonable price. Now the items comming from China are much beter. I used something like that old generator about 25 years ago tunig some coil and capacitors. As I needed them on a exect frequencyto make a filter. I used a freq counter to set the generator. Had to keep one eye on the counter to make sure the generator was not drifting. I would have loved to have the China generator I have now. Digital readout, just set the numbers and it stays put in the audio range.     Spearking of repairing the old gear, have you checked the price of some of the tubes and capacitors that are in the old gear ?   Even using some of the China oscilloscopes is a joy. Press a button on them and off to the side is lots of info about the trace. Voltages in RMS and peak to peak. Even the frequency. That will take the place of a voltmeter in many cases.   After fighting using the old test equipment for years I finally got to the place where I could get the more modern equipment. Sure makes things easier to work on when you can depend on the test equipment and not have to wonder if it is the test equipment or the item to be repaired. Like the old signal generator may have some slight hum on the signal and you may think that hum is comming from the unit under test.

"Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com>: Mar 13 09:15PM <oldschool@tubes.com> wrote in message news:vaicccta9pdjea9abbc1074l06705f6677@4ax.com... > from the 70s. Because I like that old test gear, I'd be happy to get > either of these, or another similar. Both of these are Sine and Suqare > Wave.   Plenty of cheap function generators out there that do the basic sine, triangle and square-wave.   Its worth checking the spec - if they start with sq-wave and convert to triangle and then sine; the sine could be a bit lumpy.   Starting with sine gets better wave purity, but accuracy is not so good and the sq-w M/S ratio can be off.   There are some good articles out there on testing audio response with other waveforms - a perfect square wave is the sum of an infinite series of sine waves. Taking that the other way round - a half-decent square-wave can tell you as much as a lot of different sinewaves all at once.   At one time it was trendy to test audio with sawtooth, but I haven't seen any new articles recently.

Martin Brown <'''newspam'''@nezumi.demon.co.uk>: Mar 14 09:22AM On 13/03/2017 09:32, Jasen Betts wrote: >> audio signal into amp sections to dee if the audio is passing that >> stage.   > Any reason you've not looked at PC software?   Indeed. I favour Daquarta (sp?) for this sort of thing.   The paid for version will even give you a realtime FFT vs time waterfall plot of the input signal and the signal generator part continues to work after the evaluation period. It can do the usual waveforms well enough for all but the most demanding tests.   It is easily good enough for most audio work and allows you to see harmonic content of signals in realtime. The only disadvantage is that it perhaps isn't going to like mains voltages on the inputs/outputs of your PC so you would need to be careful.   >> what DDS means).   > look it up on wikipedia. it means that inside there's some sort of computer > generating a digital wavform, that gets converted and comes out the output   There used to be old school analogue function generator chips that made a triangle wave and then applied diode shaping to get a pseudo-sine wave. HP made one design implementation that was surprisingly good. Intersils 8038 was the poor mans alternative for DIY.   http://www.intersil.com/content/dam/intersil/documents/icl8/icl8038.pdf   These days DDS is probably the way to go since it can do so much more. Testing power amps it is wiser to use frequency shaped noise rather than pure sine waves since you can hit mechanical resonances and damage acoustic drivers with quite modest power levels of pure sine wave.   -- Regards, Martin Brown

Phil Allison <pallison49@gmail.com>: Mar 14 03:14AM -0700 Martin Brown wrote:   > Testing power amps it is wiser to use frequency shaped noise rather than > pure sine waves since you can hit mechanical resonances and damage > acoustic drivers with quite modest power levels of pure sine wave.   ** Fuck I hate pig ignorant, bloody crossposters !!!!!!     " ** Giant HUH ???   Testing amplifiers does not involve speakers AT ALL !!!   Sine waves are the primary and still most revealing method.   BTW,   any speaker that cannot survive short term sine wave testing is not worth owning.   You could not be more WRONG. "       .... Phil

"pfjw@aol.com" <pfjw@aol.com>: Mar 14 05:13AM -0700 Off his meds, again.

Tim R <timothy42b@aol.com>: Mar 13 11:28AM -0700 Yeah but those old leads are all sticky now, at least the ones I have.   I don't know what causes it but I dislike touching them.

oldschool@tubes.com: Mar 13 02:43PM -0500 On Mon, 13 Mar 2017 11:28:21 -0700 (PDT), Tim R <timothy42b@aol.com> wrote:   >Yeah but those old leads are all sticky now, at least the ones I have.   >I don't know what causes it but I dislike touching them.   I never ran into that. But I did have some (in the 70s) that dried up and the insulation was falling off. (Needless to say, I saved the probes, and tossed the wire in the trash).   I dont know what would cause them to be sticky, but just a thought... wipe them down with 91% rubbing alcohol? I cant try this, since I dont have any to try that on.... (If you try it, let us know if it worked).   I have a pair of the newer plastic ones, that probably date back to around the late 1980s. The wires are still soft, but they developed a tiny spot of bare wire where they enter the molded plugs on the meter end. I fixed them with a small blob of hi temp (red) silicone caulk intended for automotive use. Worked great!

oldschool@tubes.com: Mar 13 02:45PM -0500 On Mon, 13 Mar 2017 15:34:43 +0800, Rheilly Phoull   >Theres a bit of "silicon" cable on ebay. I use it for test leads or >stuff that needs durable cables. It solders much better than the cheap >plastic stuff too.   I'll have to look for that. Sounds like what I want. If it feels like silicon spark plug wires (but thinner), that is probably ideal.

Rheilly Phoull <rheilly@bigslong.com>: Mar 14 08:46AM +0800 >> plastic stuff too.   > I'll have to look for that. Sounds like what I want. If it feels like > silicon spark plug wires (but thinner), that is probably ideal.   Start with   http://www.ebay.com.au/itm/1M-Black-22-AWG-Soft-Silicon-Wire-Cable-300V-150-c-3239-/191231232382?hash=item2c8645097e:m:mPk_HULziaE-vUFaDV9nnWg

"Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com>: Mar 13 09:18PM "Michael Black" <et472@ncf.ca> wrote in message news:alpine.LNX.2.02.1703111524260.3069@darkstar.example.org... >> desk...................................... > Or a wifi adapter, so having it on a cable means you can orient it for > best operation.   How did Wi-Fi adapters find their way in?

Michael Black <et472@ncf.ca>: Mar 13 07:54PM -0400

Foxs Mercantile <jdangus@att.net>: Mar 13 12:12PM -0500 > All use Red White and Blue as their national (State) colors.   And all have the same claptrap about Blood, Purity and Honor.   -- Jeff-1.0 wa6fwi http://www.foxsmercantile.com

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