Any Oldtimers Want To Play "What Is This THing ?"

Here's one of those old things you just pick up because it's old.

It is a "portable test oscillator". That much is no mystery, but that's abo ut it.

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So I dig up a 90 volt power supply, actually by taking an old amp carcass a nd connecting between the positive and negative rails. A variac got it to t he level I wanted. It oscillates, but really doesn't put out anything. I sh ould have put the frequency counter on it but the bench was full up.

V402 is putting out a sine wave. As you can see by the print though, it doe sn't go anywhere without some sort of input because V401 is normally in ful l conduction. On the left is a device they call E402. It appears to be some sort of a cap and waveguide or something like that. I am not taking it apa rt if I can help it.

The input on the left marker "2" seems like it might accomplish a little bi t of frequency modulation, for whatever reason. The input marked "3" would seem to result in amplitude modulation.

It's not a huge mystery how the thing works, but I am puzzled as to its act ual purpose. Is it for testing recievers out in the battlefield or somethin g ? Like puts out a steady tone for everyone to tune to with their reciever s, something like that ?

I'll probably get some pictures of the whole thing soon in case anyone migh t recognize it that way. I never thought to take them, I just got one of th e schematic which is glued to the inside of the cabinet.

Reply to
jurb6006
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According to the top of the schematic, it's a "portabale test oscillator". Googling on that spelling yields this mailing list message - see item 4:

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A couple of follow-ups identify it as a test oscillator for an ARR-1 or ARR-2 navigation receiver.

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If you search for "ARR-1" in this Wiki page

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there is mention of a Navy "ZB/YE" homing beacon system that operated on 246 MHz, and discussion of how the ARR-1 and ARR-2 worked.

Matt Roberds

Reply to
mroberds

My search turned up nothing of the sort. Also it seems not to be it. The WIKI article's pictures do not conform.

I'll get some pictures, probably by the weekend or something. It is not in my immediate possesion.

Reply to
jurb6006

You got it right. Sinewave 1 tone AM modulated test transmitter for about 200 - 400 MHz probably.

The lefthand thing is a coaxial cavity resonator.

w.

Reply to
Helmut Wabnig

Learn what " does on Google.

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The Wikipedia article that I linked showed the receivers that your oscillator was designed to test, not the oscillator itself.

Matt Roberds

Reply to
mroberds

I knew that. I did try it but got no results from "qth.net". I just tried i t again and same thing. Did you follow something from there to get there ? Or did you repeat the search with the omitted results included ? It says "a bout 28,700 results" but then it only has four pages.

oscillator was designed to test, not the oscillator itself."

That splains it.

The search on Google with the quotes yields four pictures and the one on th e left looks like the thing, but clicking on it goes to eBaay. Thank you $% &# SEOs. However, it actually doesn't seem to be the same results I got the other day. I am really thinking of dumping them, both as a search engine a nd email. I got like five emails with them and really, screw it. Either tha t or don't use their search engine because the idiots give me those ads on other pages of what I've searched for, like a Digikey or something. Stupid idiots ! I HAVE ALREADY SEEN THAT !

I swear, this world just gets dumber and dumber. Like when I bought a new P C monitor, the rebates required an email, which they WRECKED with spam, gue ss selling what - MONITORS ! Stupid stupid stupid, I JUST BOUGHT ONE. What, you think I just buy these things every couple days because I got a fetios h for them or something ?

Enough bitching. I'm done for now :-)

Reply to
jurb6006

What do you input to that ? It doesn't seem like it is going to make an oscillator just being there.

Reply to
jurb6006

I lied, it wasn't "" that made the difference. Just search on

portabale test oscillator

and those qth.net results are the second hit. NOTE THE MIS-SPELLING OF "portable". It was spelled that way in your photo of the schematic, so I figured that might be a good search term.

For PC hardware, I just assume that the rebates don't exist, unless they are the kind that the store automatically applies when they total it up. Either the form has to be mailed in within 30 nanoseconds of purchase, or they want three personal references and a DNA sample, or they're spammers, like you found.

Matt Roberds

Reply to
mroberds

AHA ! Shades of my P2P days. I got plenty of stuff then with misspellings because the people who ripped it obviously didn't know how to spell. Even though it was probably right in front of them.

Reply to
jurb6006

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