I have a 3336B that I want to convert to a 3336C. I ordered a BNC to SMA cable to use in the conversion, however I mistakenly ordered RG316 instead of RG58. Both are supposed to be 50ohm, the only difference seems to be that the RG316 is for high temp applications. Will RG316 work for this, or should I get a RG58 cable?

No, since they're both 50 ohm cable it won't matter, particularly in the lengths involved.

David

I would like to do the same as I cannot find the WeCo connectors for my 3336B. Let us know how it turns out, maybe post a pic.

http://holland.dyndns.biz/testequipment/HP/HP3336B

Has sufficient pictures I hope...

David

Nice job David.

Ok, you HP 3336A/B/C experts, give me your take on this.

My 3336A already has BNC outputs. One for 75 ohm, and a couple more for 150 and 600 ohm. What I want is a 50 ohm output.

So I terminated the 75 ohm output with a 75 ohm resistor and connected my true RMS Fluke 87 Type III digital meter to it. With the generator set to 1000 Hz and the output level set to 0.0 dbm, I got a reading of 272 mV across the 75 ohm terminator.

In order to get a 50 ohm output, I simply connected 50 ohm output of the "A8 Output Attenuator" to the front panel's 75 ohm output BNC. This 50 ohm output was originally connected to the module driving the 150 ohm and 600 ohm outputs. Since I don't plan to use those outputs, I left that module's input disconnected. I also changed the internal jumper from A to C.

Then I fired it up, connected the output to a 50 ohm terminator, and measured the output. I found that if I set the output level +1.7 dbm higher, I get the same 272 mV across the 50 ohm terminator.

I understand this isn't calibrated, but subtracting 1.7 dbm from what the generator is showing should get me in the ballpark. Is my thinking correct, or have I left something out that means I'm not even close?

I think its working...

According to the table here:

http://www.jneuhaus.com/volts_to_dBm.html

0.272 Vrms across 50ohms would be about +1.8dbm, so that's right.

The Vrms voltages will vary depending on the impedence of the system. You shouldn't need to subtract anything from the display if the internal jumper is moved.

According to the same table, terminated with 50ohms, and set to 0dbm, you should see about 0.224Vrms. Which is pretty close to what I see on mine.

David

Great! That was even easier than I thought to convert, because 224mV is very close to what I am getting at 0dbm.

Do these units have a memory and/or a memory backup capacitor? Every time I fire it up it is set to 10khz, and none of the other previous settings are remembered either.

Thanks for your help!

Welcome,

Mine resets itself as well. Pretty certain its normal.

David

3336 boots to the presets programmed in the EPROMs.

Pete