Sen Herman E. Talmadge (D-Ga.) was "surprised and disgusted" when he learned that a former aide put Talmadge's name on a secret bank account containing illegal Senate disbursements, one of Talmadge's aides testified yesterday.

T. Rogers Wade, executive assistant to Talmadge, told the six-member Senate Select Committee on Ethics that the Georgia senator was so angered that he summoned a senior official of the Riggs National Bank from his home at 8 that night to open the bank and confirm that the account existed.

Slightly red-faced, Wade declined to tell the committee, which is looking into allegations of financial misconduct against Talmadge, precisely what the Georgian said when he heard about the account from Wade and from Talmadge's attorney James Hamitlon the night of Aug. 24, 1978.

But, Wade said, "it ended with a damn." He added "there was no question in my mind that he never knew of the account."

A knowledgeable source said yesterday, however, that Talmadge's former aide Daniel Minchew has already testified to the Ethics Committee in secret that he spoke with Talmadge of opening a secret bank account to convert campaign checks into cash before the Riggs account was opened July 1, 1973.

The source said Minchew discussed the idea with Talmadge in the senator's office more than a month before the Riggs account was opened.

Nearly $39,000 in illegal Senate expense reimbursements and mostly unreported Talmadge campaign contributions was funneled through the account in 1973 and 1974.

Minchew has testified to the ethics panel that Talmadge knew of the secret Riggs account and profited from it. Talmadge has denied the former aide's allegations and labeled Minchew "a proven liar, cheat and embezzler."

The secret account is the focal point of the investigation into five allegations of financial misconduct against Talmadge. The Committee's public hearings on the charges began Monday.

Minchew went to see Talmadge last June 14 after newspaper reports about questionable Senate expense claims and other practices had prompted the senator, on June 13, to order an audit of his Senate office finances. But sources said Minchew did not specifically mention the Riggs account to Talmadge during their early-morning meeting.

However, in a memo written by Minchew and delivered to Talmadge at the June 14 meeting, Minchew noted that "some time in mid-1973" he discussed obtaining extra funds for Talmadge's wife, Betty. Talmadge and his wife were at the time having marital problems and were divorced last year.

According to the memo, introduced into evidence before the Ethics Committee, Minchew said funds from Senate reimbursement checks for office expenses were cashed and distributed by him, twice to Talmadge's son, Bobby, and once, through Talmadge, to the senator's wife.

In the memo, Minchew does not explicitly mention any conversion of campaign checks to cash for Talmadge, but the document does refer to "other checks I was converting to cash for you" as well as "reimbursement checks."

Minchew said in his memo that an "awful misunderstanding" had occurred in mid-1973 about the source of the funds for Betty Talmadge. The source of those funds, the memo indicated, was a so-called "special account."

The Talmadge office maintains a special account in Atlanta for the senator's expense reimbursements as well as his honoraria, bank dividends and other legitimate sources of income. However, sources said yesterday that Minchew was referring in his memo to the secret Riggs bank account, and not the one in Atlanta.

Talmadge has denied Minchew's version of both the June 14 meeting and explanation of the memo. In the ethics panel he has called the memo from Minchew a "blackmail threat."

In other testimony before the Edthics Committee, yesterday, Wade and Talmadge's personal secretary, Rita Hubler, told the panel it was standard practice in the senator's office to inflate expense claims to the Senate disbursement office.

The overcharges to the Senate were made without Talmadge's knowledge, according to the two aides.

Payments were obtained by submitting claims to the disbursement office for nonexistent expenses charged to the Talmadge Georgia office. Under questioning the Talmadge aides conceded that the Georgia office did not have any expenses they could recall.

According to documents released by the Ethics Committee this week, the total distributed by the Senate to Talmadge's office for Georgia office expenses between June 19, 1973, and April 27, 1978, was $43,574.92. Talmadge paid back the Senate $37,125 last year for Senate reimbursements to which he was not entitled. CAPTION: Picture, Sen. Talmadge talks with personal secretary Rita Hubler after her testimony. By James K. W. Atherton - The Washington Post