AM Radio VTVM Alignment

[@jungle_jim42]

I've been building tube circuits for just a few years now and decided to jump into AM; building a simple AA5 circuit. Its SURPRISING how difficult it is to find info on building/tuning/test/setup of the AM stuff (at least more difficult than HiFi and Instrument related info). It's out there but not nearly as condensed, so i wanted to say thanks for a no-fluff, thorough run-through for AM setup!

[@EzeeLinux]

Great video... I learned this back in radio engineering class many years ago... It was nice to revisit the process once again. :)

[@tubeDude48]

At 4:15 you can also tune to 9.10KHz as well. That's a harmonic of 455KHz.

[@paublusamericanus292]

I find the fundamentals of tube radio, and frequency manipulation fascinating. Always playing with the waveform, to get it within tolerance, for its specific application. And moving from early simple wave frequency, to later, waveshape, and manipulation. forming the wave into the proper shape for fm or higher functions with special instruments to shape the wave better.

[@bandersentv]

You're welcome, I'm glad you enjoy the videos. AC volts. You better not have DC across the speaker or you'll burn it out ;) I'm no expert on tube testers by any means. I have the ones I have because I found good deals. Of the testers I do have, the Hickok 600A is the most accurate (mutual conductance), Knight 600B handle wides variety of tube types but is only a basic emission tester. Good luck.

[@erin19030]

The WV98 is merely a basic service tool and not precision lab test equipment. I have one made by VIZ who took over the RCA test equipment division. Its made just as skillfully as the earlier RCA models and is a true pleasure to own and operate at my test bench. Once a year I get it calibrated by an authorized calibration service , when at that time I replace the batteries too.

[@RayMillTN1]

Excellent video - I too am relearning some of my electrical knowledge and just happen have a VTVM (EICO 250) and a vintage tube radio. I will definitely use this knowledge you have shared.

[@bandersentv]

Raymond Tant Thanks - I'm glad you enjoyed it

[@nor4277]

Some great and helpful info ,I just bought three differ heath kit vtvm hopefully ,I can get the up to snuff so mine can be useful as yours.,thanks for showing the use of the vtvm .

[@mrGoesto11]

Thanks for the great instruction, especially showing us several ways to create a signal into the radio & the relationship between the generator & freq counter. My only suggestion is to point the camera at the "hookup" points rather than just stating you "hook up" this to that.

[@bandersentv]

My thinking was that it's going to be different for every radio. You need to refer to a schematic and trace out the wiring to find the right hook up point

[@theonewease]

Thanks Bob! Thanks for your vids and also a shout out to the other guys you probably know... AllAmericanFiveRadio, RestoreOldRadios, radiotvphononut, I just completed my 1st AM radio alignment...after acquiring and restoring my RCA VoltOhmyst Jr and Eico 324 just to do it. How Freaking Cool!!! BTW... it was a Flea Market RCA 1X2 that I overhauled. I've watched all of your Radio & Parts vids and some of your TV ones too!

[@bandersentv]

Hi and thanks. I have encountered some tight cores, but luckily not so tight I couldn't turn them with a little extra force. If I did, I'd try spraying a little electronics cleaner or contact cleaner to lubricate the core without harming it.

[@TempoDrift1480]

Cool man, thanks for getting to the point. Some other channels are too "showy" and it makes it hard to focus with all the distractions. "I'm gonna move the camera so you can see..." Okay well move the camera. You don't have to tell us. Some folks like to explain how they're gonna remove a screw and it's like well just do it already. I can't stand it when someone feels the need to narrate every movement. "I'm gonna walk around back, and I don't know if you can see this on camera"...Thank you for sticking to the purpose of the video. Very easy to understand.

[@LE5SONS]

I used to spend hours messing about tweaking those rf chokes, thanks for bring back those memories :-)

[@bandersentv]

You're welcome - glad you enjoyed it.

[@bandersentv]

The Fluke 27 I recently picked up has one of those bar graphs too. I can see how it'd be useful for peaking coils.

[@jdsweet3657]

This is interesting, I'm getting ready to calibrate a small AM transmitter/receiver I'm working on. I decided to put a voltage transformer on the output to separate the audio but drive a couple antennas instead of loudspeaker.

[@mrGoesto11]

One of the best instructors for vintage tube gear online. How about doing one on calibrating a Simpson VTVM Model 312?

[@bandersentv]

Sorry but I don't have a Simpson 312. Try asking on the Antique Radio Forum in the test equipmet area

[@aircooledcamper]

I have used a Fluke 117 DMM with a 1MΩ resistor in series with the point of the lead as the meter has a 10MΩ+ input impedance and a 33 segments/second bar graph. The digital display updates at 4 times/second--if I recall correctly. It worked well, so I can't discount a quality DMM for alignments. However, I have recently bought and calibrated a Simpson 312 VTVM and used that one on another alignment job. The digital works well, but the VTVM is certainly more enjoyable, for me, to use.

[@bigaudioal]

Thanks for your message. Analog meter and voice coil circuit. Got it! Really appreciate it! -Al

[@brickson98m]

Wow! This is very complicated to an uneducated (about these things) person like me. I'm hoping to slowly learn, as I will be getting an old radio passed down to me from my grandparents, and I'm not sure the condition of it (electronically) after all these years. It seems to be in decent working order, but I haven't messed with it much since I was a child.

[@zundfolge1432]

how old a radio? If you want it to last a long time, it needs to be checked out. Old capacitors often short out, and when they do they can damage other components. Best to check and replace all capacitors/resistors ect, or you might find your radio suddenly quitting.

[@jonmullins8460]

This is precisely what I needed. Thanks for taking the time to make this.

[@clocksandradios]

superb, I am just learning, thank you for spending the time doing this.

[@bandersentv]

Thanks! Glad you enjoyed it.

[@mikesamra9126]

Love all your videos. i use my Viz Volt Ohmyst a lot in audio but you can use a Fluke on the detector and not worry about loading the detector being it's 11 meg/volt. I know you know this but I wanted to mention to others as I had a guy ask me this question 3 months ago. I always post your videos on our vintage audio forums and antique radio forums because you explain to sell and they can see first hand how to do a lot of these procedures.

[@gberlucchi]

Your explanation is very clear. Thank you.

[@billybonewhacker]

great vid man. ive got an old grundig majestic that may need a going over.this realy helps ive read somewhere that some s.w. if freqs are set at 1600. ty

[@bandersentv]

Yes, you can use a modern meter, but remember to connect it to the voice coil - not the primary of the output transformer. Also, use an analog meter rather than a DMM. You'll have a very hard time finding the peak with a digital meter.

[@guitarpro248]

Perfect! You answered my question!

[@guitarpro248]

I just finished recapping a Philco transitone model TH-3 I'm on the ARF as michiganamps, do you have any tips for aligning tuning cap trimmers without a signal generator??

[@erin19030]

I love this meter !

[@dneitzke]

very good presentation , ironically we have similar test gear,

[@DubiousEngineering]

Really useful, thanks!

[@bandersentv]

I'm glad it was helpful. I've been getting a lot of requests for more alignment videos and plan on making more. I think I could do a better job explaining the process and have new equipment to demonstrate.

[@jdsweet3657]

Thanks, I'm trying your method to calibrate, but I'm using a transformer's coil as part of the tuning circuit so the transformer is bidirectional for transmitting and receiving. I'm sending a sine wave into the circuit through an audio in, and trying to see if it can help with demodulation. Quite the project though. I'm going real low though from 1hz to 22.050 khz AM.

[@djfrank59]

Hi Bob, sounds good, let me know when you're ready...I'm also looking for an old EICO 460 Scope, I need one at home and I don't want to take my Tectronix from the studio; I need it there all the time...

[@bandersentv]

Thanks, I'm glad you enjoyed it.

[@Tysman909]

Hey audio equipment :) great job on the alignment.

[@tubeDude48]

You might mention that the ground for the VOM should be the 'circuit' ground, NOT the 'chassis' ground.

[@Kennynva]

Another thing to watch for is..when you put the radio back into its case...you might have to readjust the antenna trimmer...especially if it is a metal one..

[@brockallentaylor]

Great video! Very easy to understand.

[@bandersentv]

Thanks. I'm a little embarrassed at the poor video quality though. I've gotten a much better camera since :)

[@djfrank59]

I've been looking for an old RCA WV98C VTVM...Mine got stolen some years back...They're not too easy to find these days :)

[@heidirodmarsh658]

now that was honestly informative..ty..

[@stevea5407]

My signal generator does not have modulation can I still align my set with it just setting it to 455kcs? Very good video for a valve radio beginner like me just what I needed ,thanks very much for sharing.

[@bandersentv]

Sorry, but no. Without modulation there will be no audible tone for you to hear to peak or for your VTVM to measure. Look around on ebay on the Antique Radio Forum classifieds for an inexpensive RF generator with modulation. Good luck.

[@scorpiocat69]

Hi BAndersen; This IS GREAT!..Getting back into the TechElect "stuff" after a lifetime away, and this really helps.Think I have the same RF-Gen, a Heath F-1, got it on ebay. One question: AC Volts across the spkr or DC? Also: Any suggestions on a tube tester would be appreciated; EICO, B-K Sencore? Thanks very much! Glad I subscribed.

[@robertpendergast2620]

Hi--real clear explanation. Do the multiple coils and adjustment capacitors interact with each other such that you need to go over the adjustments several times to optimize them?

[@bandersentv]

No they don't interact as each stage is shielded and isolated. It's a good idea to run through the alignment twice though. Especially if it's really far off.

[@gberlucchi]

Hi Bob Another great video. Where does the low side(black lead) of the signal generator get attached? I assume its the chassis but I am not sure. Also, what is the purpose of the .01 cap? Thanks Gary

[@THOMMGB]

I have a lot to learn, but I did save this as a "favorite" so I can come back to it when I'm ready to try the procedure. Any advice on getting a VTVM or signal generator? Thanks a lot. Tom

[@bandersentv]

That could be. I haven't work on any SW ham receivers yet.

[@erin19030]

A VTVM is overkill where a VOM will do just as well if not better. The VTVM responds to erratically at peak measurements where the VOM on the output function indicates a smoother transition to abrupt spurious signal variations.

[@bandersentv]

Good points but I actually don't have a VOM. If I ever come across a nice Simpson 260 for a reasonable price, I'll pick it up.

[@bigaudioal]

Great video!! I just picked up a signal generator to run an alignment on a 1936 Philco 610. What type of output meter can I use. Can I use a modern voltmeter hooked to the speaker leads?

[@mikedevita7184]

Hi, Love the video. question: have you run into situations where the IF can alignment adjustment core or screws are extremely tight, and what have you done in those cases?

[@cumberlandriverlily]

One thing I didn't notice was how you had the signal generator and VTVM grounded each step - is the chassis of that particular radio a hotchassis?

[@carlrudd1858]

I just 'Thumbs Up'ed you to 455! That's irony!

[@bandersentv]

Haha. Thanks for the like

[@brianbuell5569]

I don't have a VTVM, or an analog meter for that matter, but what about an oscilloscope? Obviously that would have a nice instantaneous visual like an analog meter, but does it have a high enough impedance that you don't need to test off the voice coil? Also, you soldered the capacitor used in line with the signal generator. Any reason you didn't/couldn't use an alligator clip, just to make things easier?

[@davedavis4285]

Wish I could find a local that does alignments, have several vintage portable radios that need it.

[@bandersentv]

Check for a local ham or vintage radio club

[@davedavis4285]

bandersentv I have inquired on a couple local repeaters, but no luck.

[@bandersentv]

Good luck!

[@Kalkaekie]

Good video !

[@gberlucchi]

Can you explain the use of the internal and external modulation on the signal generator. For the IF cans adjustments, was it set to external and for the antenna adjustment was it set to internal? I have been using internal modulation for the IF can adjustment but I am not sure if this is correct. Thanks

[@raven21633]

The needle's broken off on mine too :D I have a question about hooking your scope up to a signal generator. I recently picked up a nice little 35Mhz dual trace scope on Ebay for about $50.00 to learn how to use a scope. The scope is in surprisingly good condition, apart from needing a little DeOxit on the alpha channel pots. I would like to hook it up to my Eico 324 Signal Generator, but I don't want to damage the scope in the process. Is this just a direct connection? Or is there some special trick to this, such as attenuation, that I should know about? Thanks in advance. :)

[@Kennynva]

Nice video....is there any way to build a signal generator that works at 455khz????

[@bandersentv]

Sure, but I think you'd be better off just buying one or maybe building one from a kit.

[@latasha66]

will a VTVM detect ghosts?

[@bandersentv]

No idea. Give it a try and let me know ;)

[@Washburn-rr5eh]

Yes it does detect ghosts. I was able to communicate Casper and the ghost busters.

[@kermitmawyer1743]

Yes.

[@bobroth1951]

Hi, I have a radio in which the stations come in on the wrong end of the dial. Is this caused by the alignment being way off? Or is the radio just messed up in some other way? Someone may have tightened the alignment screws. Can a radio that is possibly this far off be aligned properly? Thanks, Bob

[@bandersentv]

More likely the oscillator trimmer is off.

[@Mr71chevyvan]

am i looking at a heathkit ig-102 rf signal generator? if so i need to know if when you dial in the frequency does it it shift as you release the knob ? i have 2 units that even after cleaning and lubing the vernier assemble, and the condenser bearings, both units refuse to stay on frequency. any thoughts ?

[@totallysmooth1203]

At around 6:30-6:57, it looks like you are pointing to the primary of the output transformer, but calling it the voice coil. I don't understand.

[@bandersentv]

I meant to point to the secondary side of the output transformer.

[@totallysmooth1203]

@@bandersentv Thank you for replying. Now that connecting to the secondary side is what we're after, then would you agree that a VTVM would be set to an AC range and not DC, since transformers do not pass DC? That is the big question in my mind.

[@bandersentv]

@@totallysmooth1203 Yes, it also means you need to use a modulated signal source.

[@kennynvake4hve584]

Do you know how to use a oscilloscope to look at the IF alignment, if so how do you do it?

[@SpiderDrummer24]

I'm currently restoring a Philco 42-380 using these items. I have a Heathkit V7 and an off-brand signal generator. However i cant seem to locate the output of the AM detector. How can you tell?

[@bandersentv]

Output of detector will go to one leg of the volume control. The other leg will go to ground and the wiper will go the to 1st audio amp.

[@SpiderDrummer24]

If you have the time, could you look at schematic and tell me which pin on which tube? Apparently l can't seem to get it

[@compositeguy4696]

Hello. I'm just getting into this hobby, and need some guidance to a good signal generator for AM/FM radios, thats not going to burn a hole in my wallet. Any suggestions? Jim

[@bandersentv]

Hi. Personally, no, but this question comes up a lot. Here are some suggestions on the Antique Radio Forum: antiqueradios.com/forums/viewtopic.php?f=8&t=393277

[@compositeguy4696]

@@bandersentv Thank you, I will take a look at that forum.

[@garys.7846]

Not recommending this unless you've done a number of alignments, have a feel for them and understand circuitry, but I've aligned radios using radio stations around 600 khz and 1500 khz with good success just listening to the audio out of the speaker. 73 de KQ2N

[@bandersentv]

I'm thinking of selling mine Maybe we can work out a deal ?

[@billmcdonald2436]

Vtvm set on dc or ac?

[@bandersentv]

AC

[@tubeDude48]

Whats the specs on your loop, (indution ant.)? Turns, size of wire, dia. of loop

[@bandersentv]

The alignment instructions specify 4 turns, 6 inch diameter of bell wire.

[@tubeDude48]

What size wire did you use?

[@bandersentv]

+Ted Mieske Not sure - just a scrap of old telephone wire. probably 22 or 24 gauge. I'm sure it doesn't matter. Keep in mind this is just for this specific GE radio. Always follow the instructions for your specific chassis when possible.

[@tubeDude48]

Understood!

[@hydrolisk1792]

@umajunkcollector LOL, nice youtube name :)

[@raulmancilla2568]

Lo kiero en español xfavor

[@olenamcquagge7777]

Where the heck does one learn this stuff? Of all the people I know, I don't think one of them would know this stuff.

[@bandersentv]

I read a lot and tinker a lot going back to the 80s. Some other guys in this hobby had mentors (AKA "Elmers") but I wasn't so lucky. I also have a degree in electrical engineering and a pretty sound grasp of the theory and math but nothing beats hands on experience.

[@erin19030]

The IF screw down story is pure urban legend BS. Bottom line is IF coils are "musentouchits" you can do more harm than good. Simply use the generator and gently , slowly manually sweep the 455 center range above and below by 5 KHz while monitoring the VTVM response.

[@harrystevens3885]

All this test gear but poor lighting! This criticism is aimed at lots of tech videos out there............

[@bandersentv]

It was recorded in a brightly lit room. The problem lies in the cheap video camera. Also this video is seven years old and I've upgraded my camera several times since. Check out some newer videos for better quality.

[@eugenetheodore2956]

Where do you have the meter lead attached? Is the ground meter lead hooked up?

[@bandersentv]

Look at 7:11. It's going to the output of the AM detector. Yes, the ground lead is connected It's going to the B- rail. You can also hook the meter across the speaker voice coil. Follow the alignment instructions for your specific radio chassis if you can. They are all a little different.

[@eugenetheodore2956]

@@bandersentv Thank you for responding. I recapped a heathkit 1m-28 vtvm & replaces one resistor that was bad. I can calibrate the dc. When I switch to ohms the needle goes further left from zero & I cannot move it at all with the ohms adjust pot. I replaced the pot and , with the battery in , the needle deflects to the right past inf. and cannot be moved. Also, the battery gets very hot. The new pot is also a 10k one. Do you have any suggestion other than the garbage?

[@eugenetheodore2956]

@@bandersentv Hello again, to follow up on my previous mail I also cannot adjust the ac. The needle won't go past 12v on the 150v scale.