How to select Audio Generator Tube amp or Radio repair D-Lab electronics 

From a once 53 year old now 55 year old "Elementary school" level electronics learner, I have to reiterate any compliments from others and thanks for all your teaching, advice and guidance in your videos. I have learned so much and actually repaired a number of Vintage and modern tube Marshall amps and even our HVAC from your instructionals. From your advice I bought a nice Iwata O scope and now am in the market for signal generator. I appreciate this one very much to guide us not to buy one that won't serve us as well as others.

I have a LAG-27 which only has a high/low range switch with a fine adjustment for the output. I like the way the LAG-25 output is set-up. The 27 is doing the job for now. I do appreciate you going into the details you do for these set-ups. I'm learning a lot. I've made quite a few hi-fi and guitar amps but now I'm starting to really dig into the real outputs of these amps using these testing methods. Thanks Terry and get well!

Your channel makes me buy old gear for my repairs and amp mods. I now bought an ancient Philips tone generator (;tubes of course) as a test input!

10,000 IU D3 every day and I rarely if ever get sick. Thanks Terry, great gear advice!

Very informative, I was looking at buying the EICO, you just directed me away from tube generators and saved me a lot of money. No boat anchors for me. Thank you.

Glad your feeling better.

Great video, thanks. I was trying to find one to learn how to use mine. Looked over and saw it was the Wavetek voltage control generator model 3 VGC San Diego, California

I have one of those old HP 200 units in the que to restore. Also a Leader solid state unit. Thanks for the video Terry. Hope you feel better soon.

Hope you get well soon. Best wishes. Ill be praying for you.

Huge thank you for this video. I was hoping you would touch on this generator gear. I am getting into tube repair and I have learned so much from every single video you have uploaded. Just the Best!

Havnt had a chance to use my Eico 378 yet but its in immaculate original condition and I love it! Waiting on caps in the mail to get it working again ;)

Whatever doesn't kill you will make you stronger but hope you feel well. Thank you for the great video. Have a couple RCA WA-44C's I picked up at a hamfest and would like to restore one one of them for the fun of it.

Hi Terry, I am a real deal hunter like you, I found an HP 8904A nearly new like low hours for $60! for Audio (DC-600 kHz) And for RF I have a Fluke 6011A (10 Hz - 11 MHz) $100, I is "used' but it very stable and reliable. I love them both very much for signal requirements they perform like champs. They are also capable down to 2 mV or up to 10 Vpp on the Fluke and down to 10 uV on the HP. I feel fortunate to find devices that were in the $1100 each range new. Terry thanks for your videos and I point newbies to your help for gear and such. 73

I’m currently building an Eico 378 that I purchased as an unbuilt kit. The meter is actually not used for displaying frequency, but for accurately dialing in the dB/voltage. Tuning is done by selecting from precision 2% caps instead of a variable condenser. Also, the unit uses vacuum tubes and is not solid state. Just thought I’d post for clarification. I’m having a blast building the kit. It was quite a sight to open the 52 year old box and a real treat to have the opportunity to build one. Although there was no moisture damage to the box, the power transformer was surprisingly rusty and required a bit of work. Also, strangely enough, Eico packed the kit with two momentary switches for the power and load functions. I wonder if there are any 378s out there that require the user to hold the switch to keep it powered up!

Great Video! On your recommendations I've set up a small bench and have already got my Princeton Reverb rocking again after cap job. Get better!

Nothing beats whisky and peppermint for colds, pre nyquil formula.. keeps you breathing, helps you sleep, and looking forward to the next cold🥂

I have the more modern LAG 120B. (still uses a vari-cap) It was 220v, so replaced the power transformer with a better shielded one, new power filter caps, and Cal'd it according to the manual. Works great.

Hi,Terry glad you are feeling better next time you have a visitor like the one you had turn him around and show him the door and then lock it behind him!!!.Good luck B.

Great channel. Educational, interesting, fun to watch. Love the dry sense of humor, you wacky old nut!

Mr. Carlson's Lab has a great video of a thorough restoration of an Eico 377.

Very interesting as always..

Glad to see you didn’t remove the USAF asset tag.

8:04 - I used Khron-Hite's at Analog Devices. My first job out of college back in 1979!

Thanks! I get a LAG 26 and a HP 54504A scoop.

Hi D-Lab, I used to have an RCA tube generator, not a fan. I finally got an HP8904A 0-600 kHz and a Fluke 6011A 0-20 MHz rock solid and both are built like a tank. I love both, are not get for much money now days if you look around.

Great recovery video Dlab

I like the generators built around a Wien bridge oscillator.

I love Leader equipment but currently use a HP 204D. It's an excellent generator. Most of my best equipment disappeared a few years back. Mostly miss the Leader distortion analyzer.

Terry, thank you for this information. As a result of this video I ordered an audio9 generator from EBay. It's a GW Instek GAG-810 Audio Generator, 10Hz to 1MHz. I am in the process of setting up a hobby electronics bench in my home. Still haven't gotten an oscilloscope but have a 3 amp variac. Thanks for your work.

Aw man,,,, is it possible to hit the like button on this video more than once? Lol I’m newly subscribed and have been watching every one of your videos. You’re awesome! Love the energy knowledge and experience-AND you’re just damn cool. Emi is so lucky! I’m trying to set up my test bench, and trying to learn two tube amp circuits CAREFULLY and RESPECTFULLY. What got me started is an old 1956 model R145 AMI jukebox mono amplifier. I’ve ‘wired it’ for home “Hifi” use LOL and I’ll tell you what, it sounds freaking awesome! Recently have acquired another one that I want to recap and check resistor tolerances before adding it to my system as a pair of monoblocks.

Hi Terry -nice too see you have given up the booze , you will feel much better for it and just think about all those fans out there that maybe just maybe stop drinking because you have !!! , and also things will be safer around high voltages. Great video's Thank you

Corona Virus 2020 Terry, great video!

It was good for me...thank you

Many years ago I used an Eico 378 for guitar and P.A. Repairs

Some years ago I move to digital scopes only. I use a computer for audio generator. Best Regards.

That was awesome , I prefer this to television

Happens to the best of us. Get well Terry 🤧

Wish I saw this before buying and restoreing a RCA WA-44C

Top Oscilloscope D-Lab I have the SS-3510 :)

10:08 I love D-Lab but how did a shielded BNC/MDP end get to what looks like unshielded spkr cable at the phone plug end?

I used to have an eico 377, I plugged it in to an amp without ever testing or servicing the signal generator... luckily a resistor acted as a fuse and my Mk III didn't get fried

I'm just getting over the crud as well Terry - no fun. Try a nip of apricot brandy for your throat :) Interesting video. 73, Bill.

Would the Krohn-Hite 5100-A be a proper signal generator for tube amp and solid state amp repair?

Thank You yes great video i found a Eico 378 for $50 i will try to see if it worth it, Excellent stuff. Dennis

This was excellent Terry! Thank you for sharing your experiences with the various generators. However, I was quite surprised that you did not showcase the D-Lad Audio Test Set. I have seen that unit in various videos and am really curious about it. What can it do? How can we build it?

Hi , is it possible to measure the impedance of a woofer or tweeter , with a oscilloscope and an audio generator , in differents frecuency to determine where is the ohms in a specific frecuency to determine the corrects ohms to be use in a crossover ?

HI, I really appreciate your Video's. you show the Iwatsu 5702 a lot in your video's. You also mention Leader scopes, which model would you recommend?

Super info

what about tetronix fg503 vintage solid state sound generators seem hard to find on a budget.thanks ron ps any newer models around $50 or less you can recomend?

Nice!!

Can you recommend another suitable audio/function generator, as the three you feature, Wavetek, Leader lag25, 26, and Viz are hard to find and usually in need of repair. Primarily to be used for amp testing/repair.

I know this video is very old, but just watched it now and have to add, I believe Krohn Hite devices are made in Massachusetts, not Germany.

My Heartfelt Condolences!

Hey, long-time viewer of your videos here, I go back to them several times to get good advice to start fixing tube amps, I bought that Iwatsu ss-5702 you recommended for audio work, really happy with it (except that they are extremely vague about what is exactly the calibration signal it puts out from CAL OUT, their stated .3V is more like .16V on my DMM and on the screen of the scope, anyways...) I also just bought a Wavetek 131A signal generator but the frequency it puts out seems to be wayyy off, I need to dial 1.75kHz to see a 1kHz wave on the scope. Compared it by ear with a sig gen app and another website, and sure enough, I need to hit around 1.75kHz on the dial to tune it to 1kHz. I cannot find on the Internet any discussions of people having the same issue on a solid state sig gen, does that ever happen? For a sign gen to be that out of whack? so any leads would be welcome here!

What’s pros and cons of using online signal generator instead of the a stand alone one? Thanks

terry. i looked till my eyes turned blue. do you have a video for the newbie just setting up shop? just retied and this would fill in those long mich winters.

What model is that wavetek? Looks like 142 but Google search returns a slightly different device. Yours seems to have once been in military service

Social distancing... Ocean Spray Cranberry... Terry was ready for 2020!

Hi what kind of adaptor do you need to go from the banana plug on the audio generator to the 1/4” into the amp? Does there need to be anything special or will any banana to 1/4” do?

Just letting everyone know that there are modern options out there that are very accurate, reliable, and inexpensive. A Sainsmart MHS-5200A is a 2 channel digital Function Generator, it's $75 on Amazon. It will do every wave form you can think of and it has adjustable amplitude up to the 3rd decimal place (V). It's also 1/5 the size of my Eico 378 that just gave up the ghost.

Thanks for the great content! I have an old tube style Lafayette generator that is missing the thermistor that I believe provides the bias. The unit only generates square wave and the freq is not evey close to being accurate. Does anyone know how to evaluate what thermistor should go in there? I have the manual and schematic, but there is no rating provided for the missing item.

I sure wish we could spend a little more time on the cable connection on this. Is it a shielded bnc to a 2 prong at one end and a jack at the other? If so, how is it wired at both ends, is polarity an issue, how does the shielding get treated? Please someone tell me!

So,Good.

What Wavetek model is that?

i use a GW analog sig gen

Would the volume control on an iPad or smartphone have enough attenuation for testing guitar and stereo hifi amps? Both my iPad and phone have FREE FQ generator apps installed and I bought stereo 3.5mm x 1/4” mono + BNC & RCA adapter cables to plug into the iPad headphone jack. Thx.

Good solid information as per usual Terry,could we see some more productions on the different types of phase inverters, the best one to use and tube types for this position,best regards Colin G1PGI (UK)

I have subscribed also.

Thanks for this video sir. I have pesky dogs I need to quiet down with a tone between 20kHz and 35kHz but also puts it out with good power like 20 to 40 watts. My tweeters can go up to 40k and handle 100watts. What would you recommend sir? Thank you in advance.

2nd thx terry ;-)

Cheap solid state service grade audio gens are less stable then lab grade tube ones. The HP 200 series is the best bet all around. Easy to keep going and as clean and stable as matters until you have a serious distortion analyzer, and that will usually have a generator of its own.

What are thoughts on a GW Instek GFG- 8219A?

There are very few of these available today, any one of the 3 preferred are hard to find, in my case it's been impossible so of what's available, is there anything that you would recommend?

Hi Terry, what are your thoughts on the Kenwood AG-203A? They seem to pop up at decent prices quite often. Thanks!

I would use it as a musical instrument has a synthesiser

We will control the horizontal. We will control the vertical. Extra points if anyone knows where this came from.

Who the heck coughs on people? That's just gross. Cool video, I thank you for taking one for the team.

ah ah aah aaah aaaaaaaaah AAAAHHHHHHHHHHHH CHEEEEEWWWWWWWWWWW! slobber slobber slobber... Cranberry juice gooood, don't forget that kelp! Big knobs are very important, make for great props in 1950's B movies! (see my opening in my new Hodge Podge 32 vid)

What is an audio generator?

I never wash my hands, I eat food past the date, and I never get sick, because my immune system is always running full tilt.

Check your email for old Indian remedy. Thanks for the video.

I guess Ian's mommy never taught him not to share?

What's your opinion on a Wavetek Sweep Generator model Model 134, please?

Why do you say "antenuator" when talking about an "attenuator"?

I have seen this vid 4 mouths ago and get my 2nd LAG 26. Now I have a problem whit my LAG audio generator. This is a physical problem. The isolated button that connects the variable capacitor to the shaft is broken. here a movie: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4GTgdftFjyQ.html i need a replacement but cant find it here. Can you help me?

it's OK to be: a germophobe. seriously...being sick sucks.

At-TENT-UATOR not IN-TIN-UATOR. You’re dynamite otherwise though.😎