Sun 23 Apr 2006
Once more, Google does the business! I typed in ‘precision series e-400 sweep generator’ and within minutes I found several really useful links.
There’s a few photo’s up on my Flickr account, but here’s one for starters.
Sweep Generator Innards
Originally uploaded by steamshift.
So on to the good stuff…
Technorati Tags:
hardware, technology, vintage, electronics
First up general information from www.radiomuseum.org:
Sweep Signal Generator E-400 (E400) Radio Precision Apparatus
| Country: | United States of America (USA) |
| Year: | 1948 |
| Manufacturer/Brand: | Precision Apparatus Co. Inc.; NY |
| Type: | Radio Repair Equipment |
| Model ID: | 75856 |
| Wave bands | Wave Bands in notes or not known yet. |
| Power type and voltage | Alternating Current supply (AC) / 110 Volt |
| Material | Metal case |
| Valves / Tubes | 8: 6J6, 6C4, 6C4, 6J6, 6C4, 6J6, 6X5, 0C3 |
| Notes: | Generator frequency 2-240 MHz, sweep frequency deviation 0-1 MHz and 0-15 MHz. |
Great stuff. I now have confirmation that it was made in the US and runs on 110v - very useful (though I will need to figure out how much current it draws so I can get a sufficiently rated transformer). Also very useful to have the list of valves; on the site, there are links to data about each one, with alternatives.
Secondly, thanks to Paco - a page with links to loads of manuals to old electronics, I found this:
E-400: Manual for Precision E-400 Sweep Signal Generator. Compliments of an unknown contributor.
Awesome. It came down in djvu format which I’ve never heard of, but I was able to get an application to open it from here. A quick PDF export later (I love OS X!) and I have a really useful PDF manual of how to use the Sweep Signal Generator.
So, from the manual we have the following description:
The PRECISION Series E-400 Sweep Signal Generator is a wide range multi-purpose frequency modulated Signal Source specifically designed for alignment and service of television, F.M. and other high frequency type receivers and circuits.
Great. So now I’ve got in depth info, what can I do with the thing? For now, SteamSHIFT out.
(Thanks to Paco and Radiomuseum.org.)
April 24th, 2006 at 2:13 pm
Makes a lot more sense what it is for now, but I too am struggling to think of an application. It might be interesting to try linking to a TV and seeing what you get on screen. Tv pictures must be encoded within one of thefrequency bands though so I suppose the best you could hope for would be a blank screen and that would occur if the tv was tuned to the same frequency as the generator was outputting. Im guessing really!
April 24th, 2006 at 2:18 pm
That’s pretty much the direction I was going with my thinking. The other thing that is potentially interesting is that there is a speaker in there - if you look carefully at the photos you should be able to see it. I’m guessing that means it makes some noise! That could also be useful.
April 24th, 2006 at 2:22 pm
I also have a suspicion that I’ll need an oscilloscope in order to make much sense of it. Assuming I can figure out how to connect it!
July 7th, 2006 at 2:02 am
hello,
i need a manual for my e 400 and i cant get it to down load from your links. can you send it to me?
thank you,
jeremiah raab
p.s. you can pick up a cheep o scope from ebay
February 28th, 2007 at 9:45 pm
I have a Precision E-400 Sweep Generator that I have used for many years in electronic device diagnosis and repair. I would be glad to share with you how to use it. Yes, you do need an oscilloscope to make it useful. Connecting it to your TV set will probably not have much effect unless you do it correctly. And that is NOT a “speaker” inside, it is a variable coil or inductor that is used to “sweep” the oscillator.
March 1st, 2007 at 11:06 pm
Will have to look out for a cheap scope then! In principle how does it work? Thanks
November 2nd, 2007 at 3:24 am
My Precision E-400 looks similar to the one shown here but is a rack-mount version and radically different inside. The power supply is the same basic configuration (6X5 rectifier, 0C3 regulator) but there are 4 type 6J6 tubes on the upper chassis along with the EMR (electro-mechanical modulator) and one 12AU7 on the crystal oscillator section. The 12AU7 socket is mounted to a round bracket attached to the rear of the crystal selector switch.
The manual on BAMA does NOT match the version I have, which has recently experienced a component failure which I’ll need the correct schematic to repair.
Anyone know where to find the correct schematic for this variation of E-400?
November 8th, 2007 at 8:17 am
Since posting the previous message, I have obtained a second matching set of E-400 sweep generator and companion E-200-C marker generator. These models seem to have gone through design changes and have distinct differences from one production run to the next, but have cosmetic differences which easily distinguish units of different production runs. Much like Fender musical gear, these units have “blackface” and “silverface” versions with subtle differences inside and out. For example, the EMR “ElectroMagnetic Reactance modulator” component very closely resembles a square-frame 4″ PM radio speaker in the “blackface” models, while the “silverface” EMR looks more like the “compression driver” assembly from a horn-type hi-fi “tweeter” speaker. The earliest “blackface” versions of the E-200-C also used all “octal” tubes and had a “fundamental” frequency range of 90 kHz to 30 MHz (up to 120 MHz using harmonics) in 6 bands, where the later “silverface” covered “fundamental” frequencies from 90 kHz to 60 MHz in 7 bands and up to 240 MHz by harmonics.
The manuals posted on BAMA are apparently for mid-production versions of both units. Of my two pairs of these units, neither exactly matches the manual. One pair appear to be older than those described in the manual, while the other pair are clearly of somewhat more recent vintage.