I'm having trouble getting past the yellow force fields in the Military Base. I have no trouble walking through the red ones and sucking on the damage. No big deal.
If I use my tool and repair skill on the emitters for the yellow fields, I get a message that says "the force field has been temporarily disabled" but the force field is still there and I can't get past.
The only way I was able to get past a yellow force field was by setting off some plastic explosives. But I only had one set with me, and there are two yellow fields between me and the elevator to level 4. So I was stuck.
At one point, I was able to use a computer on the right side of level one to shut down "some of the fields" after I played some blackjack. But I didn't save and when I restarted, I was never able to get that computer to work again. So I got frustrated and started shooting everyone in sight. And then I got stuck just outside the elevator to level 4.
Does anyone have any suggestions?

get a radio off one of the super mutant guards from outside of the base. use the radio on the computer where you played blackjack. that should calibrate the radio with the force fields, which will allow you to toggle the force fields on and off at any time using the radio.

I tried that, but it didn't seem to work for me. I'm pretty sure that when I tried to use a radio on the computer, I got a message that said "that does nothing". It was either that, or I couldn't use the radio "on" the computer - it didn't let me click on anything after I clicked "use". I'll have to double-check and make sure that I'm using a radio from one of the guards and not one I brought with me.
Do you have to use the Radio on the Computer after you win the Blackjack game?
Should the radio be one of your two active inventory items?
Is there a message that you get that tells you that you've calibrated the radio?
Once you've calibrated the radio, do you use it "on" the emitters, or do you just click it to toggle everything?

it's tricky, and it actually took me awhile to figure out how to "use" items in fallout 1 as opposed to fallout 2, which defaults with a "use" option for all items, not just some of them.
to answer your questions, i'm pretty sure you use the radio on the computer after winning blackjack.
in order to "use" the radio on the computer, it cannot be one of your two active items. right-click and hold on the computer and you should get a drop down menu, similar to the one you get when right-click and holding in the inventory screen. the menu should have a hand icon, which is "use." you'll then be taken to a screen that has the items in your inventory, minus your active items. just select the radio.
there will be a message to tell you the radio is calibrated. i'm sure there is a science roll involved, but if you hacked the computer you'll be fine.
you don't need to use the radio on the emitters. put the radio into one of your active item slots and just click it. each click will toggle all the yellow fields on or off for the entire level you are currently on. you'll have to toggle the fields each time you use an elevator and go to a new level.

Also, it definitely works with a radio you brought to the base, as I did it like that. The first time I tried to wire the radio with the computer I failed, but I think the error message quite clearly (although of course not literally) said "This is possible, you just failed at this attempt".
This is one of the not so few things in Fallout 1 I am glad I read about before I encountered the situation, as I guess I would have never been able to figure this out myself.

Thanks for the help, everyone!
I think I'll be able to get it to work now. I just need to be patient and win the Blackjack again.
I'd always wondered why you could right click on an NPC or object and then open up your inventory. I never realized it let's you "use" inventory items on the person you're clicking on.
One thing that I noticed as I was leaving is that all the yellow forcefields on level 1 all turned on after I returned from the lower floors.

one quick thing... i was wrong about the hand icon, it's actually a backpack icon that opens up the inventory with a right-click and hold.

I was able to calibrate the radio and finish off the base. It doesn't look like winning the blackjack hack thing is needed.
I was actually able to keep Dogmeat, Ian, Tycho and Katja alive all the way through to the end. Force fields are great for keeping them out of harms way.

A few minutes ago I was struggling with the same thing. With your information I found the tool can be used to get the "forcefield has been temporarily disabled" message, which of course doesn't disable the forcefield as you found out, BUT, if then you simply click on the emitter with your normal cursor (keep trying) then you can toggle the forcefield on/off as if the tool had let you install a switch. Yay!

Edit:
I had to use my repair skill too, maybe the tool isn't important.

I'm wondering about how you are supposed to know this? Are there hints in-game (I didn't find them)?