Hewlett Packard 3320b ??

[kf6pqt]

C&H Surplus in Pasadena Ca is gonna call it quits, and everything is half off... or negotiable, as it seems.

Got said synthesizer, and enough electrolytic caps for my next two amp projects, and that skinny WWII mic plug for fifty bucks.

So, back to the 3320b, I just drug it in... Its solid state, right? Do I need to variac it first before powering it up?

Anybody else use one as a VFO ?    Anybody got a pdf manual?

Thanks,
Jason kf6pqt

[Mike/W8BAC]

No special treatment needed before you fire it up Jason. One thing you do need to be careful of is making sure you don't have any voltage at all on the intended hook up point. The output of the 3320B is DC coupled and will fry fast.

The 3320B uses a series of vacuum reeds switched by magnetic fields to do a bunch of switching and these field windings and reeds grow old. The last time mine was in for calibration a few of these switches had problems and the repair was only somewhat successful. At times after an hour or so rf output just stops.

It is a Really nice synthesizer. Hopefully yours has low hours and will give you a long and faithful life. Good score. I wonder how much they are going for?

Mike

[kf6pqt]

Thanks Mike,

DC coupled means.... I need to put a capacitor between the 3320 output and any sort of circuit with a tube in it?

Thanks,
Jason

[kf6pqt]

So it seems to work, seems to be somewhat accurate... just the signal is noisy when listening to it, (in cw mode) only good way I can describe is it sounds like "RRRRRRRRRRR."

Is it supposed to be like that?

[w3jn]

Something's wrong with it.  It shouldbe a nice, clean CW signal.  I'd suspect filter caps, it's early 70s vintage and it's probably about that time.

I use a HP3325a with my GPT-750.  I would be very leery of using just any random synthesized sig gen as some have decidedly sub-par phase noise performance.  The 3320 and 3330, as with my 3325, should be OK in that regard as they have been carefully designed to minimize phase noise.

Although I do notice phase noise from the xmitter on the spectrum analyzer, I've asked several guys on the air if they noticed it and nobody has.  Some who run riceboxes into amplifiers can noticibly raise the noise floor on a nearby QSO, I've noticed.

[WBear2GCR]

C&H Surplus in Pasadena Ca is gonna call it quits, and everything is half off... or negotiable, as it seems.

Thanks,
Jason kf6pqt

Crud.

Been there.
Bought from them over the phone.

Another one bites the dust.

Wish I was there with a wad to go through the place...  

Guess the industrial/aerospace scene in LA is gone down the tubes too... gone to "fabrique en Chine" like everything else...

Does Rockwell still have a surplus store?
Is the swapmeet still going on?

Ah well...

                 _-_-WBear2GCR

[Mike/W8BAC]

Your right Jason. The right cap will block any voltage. If any dc finds it's way back to the synthesizer it will let the smoke out. Check for ac as well. Since it wants to play into a 50 ohm load a resistor to ground at the crystal socket will help.

It should be a picture perfect sign wave at the output of the 3320B. Have a look with a scope. That is the best way to test it. You can get a good idea of how the attenuator is working as well.

Mike

[kf6pqt]

I'll drag my hp scope of similar vintage over to it today... (too big to use as a shack scope!)

Now is the attenuator the "amplitude" control?  I think it may have issues as well, because the output is stronger at -4,5,and 6 dBm than it is in any of the "+" or first couple of negative settings.

This is a filter cap on the output I'm looking for? Or in between some PLL stuff?  I BARELY have a grasp on tube technology, let alone this solid-state bidness!

Bear, my first clue was that the place had quite a few empty shelves... odd for a place like this, then I went back up front and read on the windows what I had missed on the way in, as I was dodging a guy with a hose dusting off the sidewalk... The place IMHO has been pretty picked over since I had discovered it about 4 years ago, though I did get a good 10v filament xformer for cheap once, as well as a half-sandwich-bag full of FT-243 xtals for 6 for a buck.... worthless frequencies, but the holders are good. They are in the 5 mhz range, someday I can try grinding one up to 40m.

The only thing I really considered blowing a bunch of cash on were some BIG dc motors... toss the gas motor out of my VW bus, throw that thing in it, wait till my work swaps out their building UPS batteries again, and find some rich tree-hugger to buy the resulting monster off of me! But decided against it...

Guy said they'll likely be open another couple of months.

Rockwell became TRW, which has become Northrupp Grumman, I've never known about a "retail store," but the monthly swap is still going. Its mostly computer stuff, but some radios goodies do show up occasionally. I like to joke with people that I'm the one who buys any and all AM gear at the swap... one month it was the Swamp Thing(tm) BC-375, for a few months it was nothing, then last month it was a really rough Seneca that I talked 'em down to $20 for, and they were probably calling me a sucker after I hauled it off.

So all thats left that I know of of the old stuff is Apex, up in Sunland... or is it Sun Valley? Dunno.

Even they have cleaned up and reorganized their yard. I think the outside is all a scrap metal business now. You can actually see all of one, and a lot of a SECOND 1940's flatbed truck back there. Yeah, how long has it been since that second truck saw the light of day?


-Jason

[W1GFH]

I didn't know Apex had 1940s trucks outside in the yard. I have seen the rows of tower sections, dummy missiles, and the trailers containing the not-for-sale-"movie props". Inside one, there is a Wireless Set #19 with Russian Cyrillic labels on the front panel, rusted NC300s and HQ160s, along with belts of fake 50 cal. machine gun bullets and mirrored disco balls. Turn right from the trailers and stroll down the lane past the radar dishes, there was a low wall of military stuff, command sets, etc. now rusted to dust. After being stacked outside in the open for 20 or 30 years, I'm sure a lot of this stuff functions as multi-generational housing for insects, birds, rats and other critters.

Pretty sure W3JN means the PS filter caps. The thing has to have a power supply in there somewhere. Yeah, amplitude control is the attenuator and if some switch positions seem funky, it is prolly the switches. Forget the reed switches, but if any are regular old mechanical type, the contacts prolly have crud, so administer DeOxit in there like Holy Water.

[kf6pqt]

Its definatly got some modulation on the signal. Phase noise, if I understand what that is correctly.

[WA1GFZ]

Wow I never walked around APEX's yard. Back in the '80s the TRW swap was great. I shipped 8 crates home when I moved back East.

[W1GFH]

Wow I never walked around APEX's yard. Back in the '80s the TRW swap was great. I shipped 8 crates home when I moved back East.

Yep. The 80s were a mini "Golden Age of Radio" when it came to swappers and festers. Deerfield was raging with stuff, prices were reasonable, there were wine, women, song, etc. (OK, I hardly saw any women, but there was plenty of wine and song).