I picked one up a few months ago and played around with it. I need to reopen and deoxit the pots and do a cap check and such. I turned it on this morning and it went to overload immediately with nothing attached. I bought it to learn the basic usage and try and tune my Onkyo TX 4500, thanks for the video
@@PackardDog sorry for delay response, I’ve been away from devices lately. So my waveteck itself needs repair itself. It goes right into overload when I turn it on. I found a video here on this channel about that issue and what to fix. Seems it’s the tantalum caps that go. I haven’t gone near it to resolve and put the Onkyo away, might sell. I inherited a Pioneer SX-1280 so that got the TLC instead
@@lego40404 Thanks. Yes, I tested the output transistors and they were good. I had several axial electrolytics that were way out of tolerance; two with ESR of over 3.5. So I replaced all the axial caps and two voltage regulators. Still overload light. I was wondering about those tantalum's. When they go, they go! :)
I just bought one of these and watched your video while I waited for shipment. Bama has the manual now for the 148a but the drawings are all clipped off (portrait page size), but at least the troubleshooting procedures are readable. Also - in the same bunch of manuals, they also have the military version of the 148a and it DOES have a set of drawings. The only thing to watch out for is that the military drawings may use different names for connectors and cables. For instance, what they call J2 is actually J5 in the Wavetek troubleshooting procedures. But I was able to muddle through it using the troubleshooting procedures from the Wavetek manual and the drawings from the military manual, and like yours I had a similar problem, except I had no output on the sync or the main connector at all, while the modulated output seemed fine. I followed the procedures and eventually it led me to check the + and - 24V on the J5 cable, but before I could even do that, I noticed that the cable was a bit cocked and just pushed it back down. Viola. Seems they have repeat issues with that connector, but at least I got a 148a for dirt cheap!! Thanks for posting the clip - I realize it's 9 years old but just know it's still helping out.
@@bandersentv I really like it just starting out. Its perfect for what I'm working on - old tube equipment. Wish it had a little higher frequency range, but the signal is crisp and it has some nice functions. Even makes my EICO 460 look sharp up to 4 MHz.
Excellent result Bob. When you opened it up I thought, with no obvious signs of distress or loose wires, this may be a head scratcher but good result. Regards - Andrew
Very interesting 👍😁 The board design and physical layout was much cleaner than I would have guessed. Those sweet wafer combo shaft switches seemed so under utilized. p.s. Liked the "towel under the DUT" touch. Watch so many other repairs where the unit is just spun around on a (grit covered?) surface. Sometimes knob face down 🤤 Thanks for the video. I'm feeling smarter already.
Great video! I've been wanting to upgrade my old function generator so I just bought one of those AS-IS one on eBay. You lucked out on yours. Be sure to DeoxIT all the pots and switches on yours to minimize issues.
Gordy...Mine was working fine, then I followed the test procedure without the 50ohm load and then it stopped working.... did I burn my opamp tranistors?
Nice lesson, good stuff here. If those blue electrolytic caps. are early 80's CDE ones , I had, & still have NOS ones since they were new. Early on I'd use them, & some failed/vented over time. More than once. Enough to have to stop using them. Just fyi. Hope that helps.
Well, I got mine (paid about $82 delivered) and I lucked out. Every thing works. All it needs is a little cleaning and DeoxIT on the switches, and it should be good to go. I really like the attenuation range on the output drive. Way better than my old B & K. Anybody want to buy a cheap function generator? Hello EBay. . Thanks for showing the Wavetek 148A.
@@bandersentv Could kick myself....shorted the leads and now overload comes on with power up, stays on, no signal at all out of main gen, only distorted signal in the AM/FM/PM Generator.... ugh....... here we go!! This thing is deep in logic! May be a bit out of my league! LOL
Really appreciate the heads up. Was about to buy one in hopes of repairing it but after reading your comments about actually repairing Wavetek equipment and this model, in particular, I'm now deciding against it. Did you find the majority of Wavetek equipment you repaired to be unstable or was it this model specifically (the 148A)? Thanks in advance.
Bob, If you find that you need to replace any of those old transistors, I can imagine you could look at the original specs for that transistor and then find some modern part that would be close enough. Probably newer parts would have higher fT specs but normally these circuits are all feedback circuits so a faster part probably won't matter. If you find the higher part oscillates, strategic use of small ferrite beads usually stops the oscillation.
I picked one up a few months ago and played around with it. I need to reopen and deoxit the pots and do a cap check and such. I turned it on this morning and it went to overload immediately with nothing attached. I bought it to learn the basic usage and try and tune my Onkyo TX 4500, thanks for the video
Hi. Sorry to hear yours has problems. On the plus side, they are fairly easy to work on. Especially compared to modern surface mount equipment.
Lego, when aligning your onkyo, how much were you able to tune with 20 mhz max on this unit?
@@PackardDog sorry for delay response, I’ve been away from devices lately. So my waveteck itself needs repair itself. It goes right into overload when I turn it on. I found a video here on this channel about that issue and what to fix. Seems it’s the tantalum caps that go. I haven’t gone near it to resolve and put the Onkyo away, might sell. I inherited a Pioneer SX-1280 so that got the TLC instead
@@lego40404 Thanks. Yes, I tested the output transistors and they were good. I had several axial electrolytics that were way out of tolerance; two with ESR of over 3.5. So I replaced all the axial caps and two voltage regulators. Still overload light. I was wondering about those tantalum's. When they go, they go! :)
I haven’t given up on it, I just bounce around with my hobbies. I’m currently building a Lacewood SE amp and trying to get our fishtank stable
I just bought one of these and watched your video while I waited for shipment. Bama has the manual now for the 148a but the drawings are all clipped off (portrait page size), but at least the troubleshooting procedures are readable. Also - in the same bunch of manuals, they also have the military version of the 148a and it DOES have a set of drawings. The only thing to watch out for is that the military drawings may use different names for connectors and cables. For instance, what they call J2 is actually J5 in the Wavetek troubleshooting procedures. But I was able to muddle through it using the troubleshooting procedures from the Wavetek manual and the drawings from the military manual, and like yours I had a similar problem, except I had no output on the sync or the main connector at all, while the modulated output seemed fine. I followed the procedures and eventually it led me to check the + and - 24V on the J5 cable, but before I could even do that, I noticed that the cable was a bit cocked and just pushed it back down. Viola. Seems they have repeat issues with that connector, but at least I got a 148a for dirt cheap!! Thanks for posting the clip - I realize it's 9 years old but just know it's still helping out.
I'm glad you were able to fix it. Maybe not HP quality, but they are serviceable and very versatile.
@@bandersentv I really like it just starting out. Its perfect for what I'm working on - old tube equipment. Wish it had a little higher frequency range, but the signal is crisp and it has some nice functions. Even makes my EICO 460 look sharp up to 4 MHz.
WAVETEK rocks, I repaired a few back in the day at a Navy SIMA Faciility
Excellent result Bob. When you opened it up I thought, with no obvious signs of distress or loose wires, this may be a head scratcher but good result.
Regards - Andrew
Very interesting 👍😁 The board design and physical layout was much cleaner than I would have guessed. Those sweet wafer combo shaft switches seemed so under utilized. p.s. Liked the "towel under the DUT" touch. Watch so many other repairs where the unit is just spun around on a (grit covered?) surface. Sometimes knob face down 🤤 Thanks for the video. I'm feeling smarter already.
Perhaps the overload indicator not lighting up on a triangle wave is due to the lower RMS voltage of that waveform.
Great! I love these equipments for making "music"
How exactly are you using it?
Great video! I've been wanting to upgrade my old function generator so I just bought one of those AS-IS one on eBay. You lucked out on yours. Be sure to DeoxIT all the pots and switches on yours to minimize issues.
It sounded like those 1950's sci-fi movies with the flying saucers at the end of your video. Pretty cool!
I used to repair Wavetek equipment especially the 148A.
Gordy...Mine was working fine, then I followed the test procedure without the 50ohm load and then it stopped working.... did I burn my opamp tranistors?
Imagine if someone nearby was tuning across the MW band with that transmitting, they might be wondering what the heck was that
neat seeing the FM waveform........
Nice lesson, good stuff here. If those blue electrolytic caps. are early 80's CDE ones , I had, & still have NOS ones since they were new. Early on I'd use them, & some failed/vented over time. More than once. Enough to have to stop using them. Just fyi. Hope that helps.
You can always use a Function Gen and Scope to measure ESR on caps. See the recent W2AEW video on that.
Interesting technique, but I rarely need to test ESR and have a dedicated ESR tester.
I often wonder if the process could be used to test for LCR too.
Well, I got mine (paid about $82 delivered) and I lucked out. Every thing works. All it needs is a little cleaning and DeoxIT on the switches, and it should be good to go. I really like the attenuation range on the output drive. Way better than my old B & K. Anybody want to buy a cheap function generator? Hello EBay. . Thanks for showing the Wavetek 148A.
Excellent! I'm glad you got lucky too :)
Cool!
I just picked one up. Great Video! Thank you! I'm looking for the operating manual. Any ideas? Thanks!
bama.edebris.com/manuals/wavetek/148a/
@@bandersentv Thanks!! I appreciate it!
@@bandersentv Could kick myself....shorted the leads and now overload comes on with power up, stays on, no signal at all out of main gen, only distorted signal in the AM/FM/PM Generator.... ugh....... here we go!! This thing is deep in logic! May be a bit out of my league! LOL
at 40:00, congratulations! you just made a synthesizer!
lol
I have used and repaired a few of these Waveteks and found them to be unstable. Enough that we decided to nor buy them any more.
Really appreciate the heads up. Was about to buy one in hopes of repairing it but after reading your comments about actually repairing Wavetek equipment and this model, in particular, I'm now deciding against it. Did you find the majority of Wavetek equipment you repaired to be unstable or was it this model specifically (the 148A)? Thanks in advance.
I love mine. Been using it for over two years now with no trouble. Same goes for my Wavetek 183 and 1002
Phase modulation is just another form of frequency modulation.
👍
Bob, If you find that you need to replace any of those old transistors, I can imagine you could look at the original specs for that transistor and then find some modern part that would be close enough. Probably newer parts would have higher fT specs
but normally these circuits are all feedback circuits so a faster part probably won't matter. If you find the higher part oscillates, strategic use of small ferrite beads usually stops the oscillation.
dirty switches, sockets, and pots lol with a few crusty solder joints from time to time will cause all sorts of quirks
I got mine from the trash-bin of my university ;-)