In a quiet Capitol largely vacated for the post-election period, a group of about a dozen House members has stirred up a vat full of controversies for the new Congress. In one brief meeting, a committee of the Democratic Caucus has proposed bold changes that include:
* Sweeping away the entire House budget process and replacing it with a new system that would wrap budget, taxes, and spending into one gigantic bill. Such a plan would upset the existing committee system, and has been termed a ''radical'' reform by its author, Rep. David R. Obey (D) of Wisconsin.
* Stifling a gang of Republican ''young Turks,'' who for the past year have staged almost daily, televised attacks on the Democratic majority during the hours following regular legislative sessions. The Democratic Caucus committee proposed limiting those ''special orders'' speeches to one hour for Democrats and one hour for Republicans. Under current rules, members can ask for an hour each.
* Checking the power of future Democratic House speakers by providing that the member elect the party whip, who is now picked by the speaker.
* Setting the stage for a shake-up in the powerful House Budget Committee by rejecting a bid from the chairman, Rep. James R. Jones (D) of Oklahoma, to continue in his post, although his term has expired.
The proposals must go to the full caucus, which includes all House Democratic members, when it meets beginning Dec. 3 to elect leaders and set rules for the 99th Congress.
Meanwhile, the changes recommended by the subgroup this week are already waking up a sleepy out-of-session legislature.
By far the most dramatic is the proposed budget process reform, which appeared to take nearly everyone by surprise, from the House leadership to the proposer. Mr. Obey had been pushing his plan for six years, and failed to win even serious consideration of it. When the caucus committee narrowly voted to back it Monday, they had no formal written version, because none existed.
''I think they're fed up with the chaos'' in the budgeting process, Obey said afterward in explaining the vote. ''We think what it does is take the demagoguery out of budgeting and put some reality into it.'' The reform is designed to force the House to make hard decisions about spending and taxes instead of arguing over symbolic budget targets.
Obey's proposal would eliminate the need for individual spending and revenue bills, putting them together with a budget resolution as a single package. The full House would not pass a budget plan until it had the legislation to enact that plan.
Obey said he has some 50 backers; but opponents include Rep. Anthony C. Beilenson (D) of California, who headed a task force on budget reform that flatly rejected his plan.
''I have been intrigued by the idea,'' Mr. Beilenson says, but he is now ''less sanguine,'' because he doubts it would work. Committee chairmen and the Republicans dislike it, he says, and it would require a huge effort from the Democratic leadership to enforce it.
What's really needed in handling the budget is ''political courage, political will,'' Beilenson says. ''If we have enough of those, any process could work.''
Rep. Martin Frost, chairman of the caucus committee that recommended the Obey plan, said he personally opposed it. The new process might mean Congress ''could go through the process and wind up without anything,'' he said, although he conceded that ''it forces people to vote on specifics.''
The proposal faces formidable obstacles in the caucus next month, since it would trample on the closely guarded turf of scores of committee and subcommittee chairmen. ''People are going to have to take a long look at it,'' says a Democratic leadership aide. ''This is not exactly a small ripple.''
The recommended change for televised floor speeches, on the other hand, is widely expected to become a new House rule. It will pass ''like greased lightning,'' a GOP leadership aide predicts.
But it will not pass without a loud protest from Rep. Newt Gingrich of Georgia, intellectual leader of an insurgent group of Republicans who have built national reputations on the airwaves of C-SPAN, the cable network that broadcasts House proceedings.
''You would think that a party that had just lost 49 states (in the presidential election) would not restrict the number of hours that people can watch C-SPAN, and I think they will fail,'' Mr. Gingrich said in a telephone interview while on a speaking tour in New England.
Gingrich has frequently angered Democrats, especially House Speaker Thomas P. O'Neill Jr. of Massachusetts, by criticizing them by name during speeches on C-SPAN.
Democrats cite cost savings as the prime reason for the change. ''They cost money, these right-wing follies,'' says O'Neill aide Christopher J. Matthews, charging that it costs $10,000 an hour to keep the House chamber open.
''The real reason is they can't win the argument, so they strangle free speech,'' Gingrich said.