Hello everyone, yesterday I took a bunch of old electronics recycling to a local computer store where one of the guys that works there is a vintage tech junkie like me, and I traded him an old Akai X-360D Reel-to-Reel tape recorder for a Zenith Royal 2000-1 AM/FM/FM AFC Transistor Radio and 2 Hewlett-Packard Signal Generators (vintage units from the late 1960s or early 1970s).

I don't remember the model numbers on the Signal Generators but I know one of them had a slide-rule dial for tuning in the frequency (and was a smaller benchtop unit) and the other one was a large rack-mount sized unit with an analog "VU Meter" and digital readout for the frequency readout including direct entry of the frequency into the generator, they both had BNC outputs and inputs and other stuff.

I did a GIS and the models that came closest to looking like the ones that I'll be getting were the models 8654A and the 8640B but I'm not sure if those are the units exactly or not as there were several units that showed up in GIS that looked like them and they had different model numbers listed for them.

What do you guys think? Was that a fair trade or not, and what is your opinions on the old Hewlett-Packard Signal Generators, I know Mr. Carlson swears by them from what I've seen in his repair videos.

Any help with this matter would be appreciated.

The HP 8640B is the best non-synthesized signal generator they made. Extremely low phase noise. It covers 500 KHz to 1 GHz. They made a down converter for it to drop the low end coverage. Does AM and FM modulation. Weak points are the gears that are shrinking and cracking (but can usually be repaired) and the little metal fingers on the switches that sometimes fall off. These sell for a few hundred dollars in good working order.

I am not familiar with the 8654A. I have 4 or 5 other synthesized HP generators, the best is the 8662A by far. Sweeps and has 5 programmable markers.

Yes, most HP SG's are good if they are working.

The HP 8640B is the best non-synthesized signal generator they made. Extremely low phase noise. It covers 500 KHz to 1 GHz. They made a down converter for it to drop the low end coverage. Does AM and FM modulation. Weak points are the gears that are shrinking and cracking (but can usually be repaired) and the little metal fingers on the switches that sometimes fall off. These sell for a few hundred dollars in good working order.

I am not familiar with the 8654A. I have 4 or 5 other synthesized HP generators, the best is the 8662A by far. Sweeps and has 5 programmable markers.

Yes, most HP SG's are good if they are working.

Well I picked up the HP HP 8640B on Wednesday and I got it home and hooked it up to try it out and it doesn't seem to be wanting to put out a test tone (400 hz or 1kHz tone) ar the frequency dialed in on the frequency readout (for example I tried to dial in .45500 MHz on the readout or 455 kHz), and when I tried to tune to the low end of the AM band on a known working AM radio the test tone couldn't be heard and neither could the RF signal unless I went up almost 35 kHz on the readout on the signal generator.

Any ideas as to what's going on here? Is my radios IF Freguency that far off or is there something wrong with the calibration of the signal generator?

How about tuning your radio to a known station, then dialing the signal generator to that frequency to see if it matches?

How about tuning your radio to a known station, then dialing the signal generator to that frequency to see if it matches?

I'm trying to do that but the output signal is way too weak for the radio to pick it up to be audible above the local station which is a 50KW blowtorch from Chicago (ESPN 1000 out of Chicago.)

.....What do you guys think? Was that a fair trade or not......

Well, considering that tape player lists for between $400 and $500 on Reverb & the Bay, and what you got might be worth 1/3 of that at best, I'd say ya'll got buttraped like Ned Beatty in "Deliverance"

"Squeal like a pig!!!!!!" ...........:whip:

Well, considering that tape player lists for between $400 and $500 on Reverb & the Bay, and what you got might be worth 1/3 of that at best, I'd say ya'll got buttraped like Ned Beatty in "Deliverance"

"Squeal like a pig!!!!!!" ...........:whip:

Not, really seeing as I really had no use for the Reel-to-reel tape recorder, because I wasn't able to find any decent tapes in the genres I liked at a decent price for it to make it worth my time keeping it, plus when I tried listing it locally in my area on places like Facebook Marketplace or Craigslist etc. I had no bites whatsoever on this tape recorder, also the guy I did the trade with is a fellow vintage electronics enthusiast like I am and a good friend of mine so I was more than willing to do the trade with him (he actually had some tapes for it that he could use with it), plus with as much as that reel-to-reel tape recorder weighed (80 lbs.) it would of cost about $200 just to ship it which would of eaten into any potential profit I could of made off the unit.

So really I don't think it was a rip off at all in that sense, plus vintage HP Test equipment in general costs quite a bit of money on eBay or elsewhere (I don't know which world you live in, but where I live you can't get a decent HP Signal Generator for under $300.)

Not, really seeing as I really had no use for the Reel-to-reel tape recorder, because I wasn't able to find any decent tapes in the genres I liked at a decent price for it to make it worth my time keeping it, plus when I tried listing it locally in my area on places like Facebook Marketplace or Craigslist etc. I had no bites whatsoever on this tape recorder, also the guy I did the trade with is a fellow vintage electronics enthusiast like I am and a good friend of mine so I was more than willing to do the trade with him (he actually had some tapes for it that he could use with it), plus with as much as that reel-to-reel tape recorder weighed (80 lbs.) it would of cost about $200 just to ship it which would of eaten into any potential profit I could of made off the unit.

So really I don't think it was a rip off at all in that sense, plus vintage HP Test equipment in general costs quite a bit of money on eBay or elsewhere (I don't know which world you live in, but where I live you can't get a decent HP Signal Generator for under $300.)


Well now, I guess your's and my opinions differ slightly here, no surprise to me. The thing is, while I didn't ask your opinion, you DID ask mine as per this quote;

What do you guys think? Was that a fair trade or not

So, since it appears you ARE satisfied with your trade as per your most recent post, why would you need the affirmation of people like me who you don't know and who (obviously) have different views about the value of the deal you made? You like what ya got? Great! Run with it and don't worry about what I or anyone else thinks, cause I certainly ain't loosing any sleep over whether or not your upset over what I think regarding if ya got porked or not :thmbsp:

Well now, I guess your's and my opinions differ slightly here, no surprise to me. The thing is, while I didn't ask your opinion, you DID ask mine as per this quote;



So, since it appears you ARE satisfied with your trade as per your most recent post, why would you need the affirmation of people like me who you don't know and who (obviously) have different views about the value of the deal you made? You like what ya got? Great! Run with it and don't worry about what I or anyone else thinks, cause I certainly ain't loosing any sleep over whether or not your upset over what I think regarding if ya got porked or not :thmbsp:


The problem I have with your "opinion" isn't the opinion isn't itself, it's the fact that whenever I (and others as well) ask about an item that we are thinking about buying or trading for, you (initforfun) act like that question was never asked so then when we do actually pick up the item in question and then ask whether or not we did good price wise (or trade wise) on the item in question, then that's when you decide to interject your "opinion" on the item(s) in question which usually ends up being some sort of sarcastic remark stating that the item in question is junk and that it wasn't worth your time, money and gas to pick up the item.

In other words you have poor timing when it comes to making your comments.

And I'm just leave it at that.

Have a nice weekend.

The problem I have with your "opinion" isn't the opinion isn't itself, it's the fact that whenever I (and others as well) ask about an item that we are thinking about buying or trading for, you (initforfun) act like that question was never asked so then when we do actually pick up the item in question and then ask whether or not we did good price wise (or trade wise) on the item in question, then that's when you decide to interject your "opinion" on the item(s) in question which usually ends up being some sort of sarcastic remark stating that the item in question is junk and that it wasn't worth your time, money and gas to pick up the item.

In other words you have poor timing when it comes to making your comments.

And I'm just leave it at that.

Have a nice weekend.

Dude, you posted about the stuff on the 16th, and picked it up on the 17th. Now, since I don't check each and every post every day here, I'd say my timing was fine, you asked for an opinion and I gave one when I saw your post. And again, I'll say that what I or anybody else out here in internet land thinks is not particularly relevant here, do YOU think you got a good deal? Even though I don't think so, money wise, there are times when usefulness trumps raw dollars, you gave up what was to you a useless tape recorder and got two tools that may help you in your future restorations, I should think you'd be happy for yourself and not need pats on the back from strangers about how great of a deal ya got. As to sarcasm, "I don't know which world you live in" is just as sarcastic as anything I've typed, it takes two to Tango and I'm perfectly fine with that. I truly DO wish you well with your new signal generators and hopefully they will be an asset to you going forward.

PS, it's "init4fun" and not "initforfun" , , , in our hobby it's best to remember that small details DO matter...... :thmbsp:

Dude, you posted about the stuff on the 16th, and picked it up on the 17th. Now, since I don't check each and every post every day here, I'd say my timing was fine, you asked for an opinion and I gave one when I saw your post. And again, I'll say that what I or anybody else out here in internet land thinks is not particularly relevant here, do YOU think you got a good deal? Even though I don't think so, money wise, there are times when usefulness trumps raw dollars, you gave up what was to you a useless tape recorder and got two tools that may help you in your future restorations, I should think you'd be happy for yourself and not need pats on the back from strangers about how great of a deal ya got. As to sarcasm, "I don't know which world you live in" is just as sarcastic as anything I've typed, it takes two to Tango and I'm perfectly fine with that. I truly DO wish you well with your new signal generators and hopefully they will be an asset to you going forward.

PS, it's "init4fun" and not "initforfun" , , , in our hobby it's best to remember that small details DO matter...... :thmbsp:

Ok, well I really shouldn't have worded it the way I did, what I was trying to say was did I do good in scoring those signal generators in general because like I said previously there are a lot of people in the repair world that think HP Test Gear is really good, and top notch so I was just trying to figure out how these HP Signal Genetators compared to other HP Signal Generators and how they fell in the model hierarchy.

Ahh, the triumphant return of Captain Clock under the Vortelexfan handle.... between you and Jeffhs (not to mention most of the good members dying or switching to groups) I've just about had it with these forums.

One thing about HP generators and other gear, there are various places on the web where those experienced with them describe the troubles ans fixes they have found. The 8640 is very popular and a search for it's troubleshooting should be helpful.

Ahh, the triumphant return of Captain Clock under the Vortelexfan handle.... between you and Jeffhs (not to mention most of the good members dying or switching to groups) I've just about had it with these forums.


If this were "Survivor" we could band together, get a few more on board, and vote the two of em off the island in a double elimination.......

Or, just wait till no one's lookin, and toss both em feet first into the woodchipper, your choice :banana:

Kidding!!!!! , , , , just kidding.......

Maybe :tongue:

If this were "Survivor" we could band together, get a few more on board, and vote the two of em off the island in a double elimination.......

Or, just wait till no one's lookin, and toss both em feet first into the woodchipper, your choice :banana:

Kidding!!!!! , , , , just kidding.......

Maybe :tongue:

Look, I'm not trying to start trouble here, but when you've been bullied all your life like I have for having a learning disability (high functioning autism) that apparently even to this day not many people seem to be aware of it and its impacts on people's lives, then you would be kind of leary of people's comments as well, whether they were meant out of spite or not.

Another key thing to know when communicating with people with Autism is that people with autism don't handle sarcasm well (we tend to take things too seriously when it comes to that because we don't pick up on sarcasm as easily.)

So when comments like the ones you make, where you give your "opinons" about something and you're talking in a "sarcastic" manner, then it would be best to not do that, and just give a straight up yes or no answer, rather than making a sarcastic remark with vague references to old hollywood movies.

Look, I'm not trying to start trouble here, but when you've been bullied all your life like I have for having a learning disability (high functioning autism) that apparently even to this day not many people seem to be aware of it and its impacts on people's lives, then you would be kind of leary of people's comments as well, whether they were meant out of spite or not.

Another key thing to know when communicating with people with Autism is that people with autism don't handle sarcasm well (we tend to take things too seriously when it comes to that because we don't pick up on sarcasm as easily.)

So when comments like the ones you make, where you give your "opinons" about something and you're talking in a "sarcastic" manner, then it would be best to not do that, and just give a straight up yes or no answer, rather than making a sarcastic remark with vague references to old hollywood movies.

Well, I can say with all certainty that I had no clue you have autism, so there is no way I was bullying you because you have it. Your right about this; sarcasm, even if meant in a more joking and less malicious way, doesn't always come across right in print, especially with people we don't really know beyond their internet personas. I do wish you well with your future electronic endeavors involving the HP signal generators :thmbsp:

Well, I can say with all certainty that I had no clue you have autism, so there is no way I was bullying you because you have it. Your right about this; sarcasm, even if meant in a more joking and less malicious way, doesn't always come across right in print, especially with people we don't really know beyond their internet personas. I do wish you well with your future electronic endeavors involving the HP signal generators :thmbsp:
Alright thanks, I'm glad we were able to work this out.
I apologize for getting upset at you, part of it was that I misread your initial posting and I thought the message said one thing when it said another.

Well I picked up the HP HP 8640B on Wednesday and I got it home and hooked it up to try it out and it doesn't seem to be wanting to put out a test tone (400 hz or 1kHz tone) ar the frequency dialed in on the frequency readout (for example I tried to dial in .45500 MHz on the readout or 455 kHz), and when I tried to tune to the low end of the AM band on a known working AM radio the test tone couldn't be heard and neither could the RF signal unless I went up almost 35 kHz on the readout on the signal generator.

Any ideas as to what's going on here? Is my radios IF Freguency that far off or is there something wrong with the calibration of the signal generator?

What test equipment do you have at your disposal? An oscilloscope and frequency counter would be nice. Maybe modulation is not working? How are you coupling signal into radio? The readout on these is just a frequency counter as they are not synthesized, so the internal cavity oscillator is working, but you still may not be getting output if the attenuator is not working. It is just hard to say from what you are describing without trying to look for signal output on oscilloscope. These are very difficult units to work on as is ALL HP equipment. If you are not experienced with these it may just be better getting a working unit. Did your friend say the unit was working? You NEED the service manual to repair these. HP has flow charts for troubleshooting, but that also requires test equipment to do so.

What test equipment do you have at your disposal? An oscilloscope and frequency counter would be nice. Maybe modulation is not working? How are you coupling signal into radio? The readout on these is just a frequency counter as they are not synthesized, so the internal cavity oscillator is working, but you still may not be getting output if the attenuator is not working. It is just hard to say from what you are describing without trying to look for signal output on oscilloscope. These are very difficult units to work on as is ALL HP equipment. If you are not experienced with these it may just be better getting a working unit. Did your friend say the unit was working?

I do have an oscilloscope, would I just hook the output of the signal generator up to one of the inputs on the 'scope and see if it picks up a signal?

As for how I was coupling it up to the radio, I was using some 50 ohm BNC clip leads and clipping them to the proper coupling points on the radio.

I do have an oscilloscope, would I just hook the output of the signal generator up to one of the inputs on the 'scope and see if it picks up a signal?

As for how I was coupling it up to the radio, I was using some 50 ohm BNC clip leads and clipping them to the proper coupling points on the radio.

Yes, you should be able to see a clean sine wave on the oscilloscope with modulation turned off. If your o-scope has a 50 ohm input use that, otherwise a high impedance input is ok but the amplitude will be a little off. Sinewave should still be clean.

Clipping the 50 ohm output to the radio is dangerous for the signal generator. You should use a .01uF or so capacitor to isolate the signal generator from the radio.

Yes, you should be able to see a clean sine wave on the oscilloscope with modulation turned off. If your o-scope has a 50 ohm input use that, otherwise a high impedance input is ok but the amplitude will be a little off. Sinewave should still be clean.

Clipping the 50 ohm output to the radio is dangerous for the signal generator. You should use a .01uF or so capacitor to isolate the signal generator from the radio.

Ok. I've got a BNC to BNC cable I'll try hooking the signal generator up to the 'scope and see if I get a clean sine wave.

It took me a while to figure out which hookup on the 'Scope to hook the signal generator up to to test the signal generator, but I was able to figure out that the signal generator is indeed working as I was able to get a clean sine wave onto the 'scope.

See picture below.

Does the frequency indicated on the signal generator display correspond reasonably well with that measured by the scope? :scratch2:

jr

Does the frequency indicated on the signal generator display correspond reasonably well with that measured by the scope? :scratch2:

jr

I'm actually working on the signal generator that doesn't have the digital readout right now, and for some reason when I hook my stand alone frequency counter up to it, it doesn't register on my frequency counter, and when I used it to "radiate" a signal to my Zenith Royal 2000-1 radio it did put out a signal including a test tone but it was kind of weak unless I touched the large N-type RF output plug with my hand then the signal came in loud and clear...:scratch2:

I'm actually working on the signal generator that doesn't have the digital readout right now, and for some reason when I hook my stand alone frequency counter up to it, it doesn't register on my frequency counter, and when I used it to "radiate" a signal to my Zenith Royal 2000-1 radio it did put out a signal including a test tone but it was kind of weak unless I touched the large N-type RF output plug with my hand then the signal came in loud and clear...:scratch2:
Well, signal generators put out a low amplitude signal. Turn up the amplitude on the SG all the way and turn up the sensitivity on the frequency counter.

Well, signal generators put out a low amplitude signal. Turn up the amplitude on the SG all the way and turn up the sensitivity on the frequency counter.

Alright I'll give it a try.

You can get a telescoping whip antenna with a BNC connector and a swivel at its base for a low price from Amazon or other sellers, and an N-to-BNC adapter, to radiate in-house signals from the generators, convenient for various tests.