This item is a vintage, 1970 era, HP - 331A audio distortion analyzer. This unit is in reasonably good condition and, in general, appears to operate as expected. Some restorative work is required to get the unit into reliable working order. Please view pictures and read description. Some notes… Physically the unit appears to be in reasonably good condition -- Front panel and meter are intact, and the case has only minor marks and discoloration due to age. Operates from standard 110V AC, and powered on normally. All controls operate smoothly and generally function as expected. Although the rotary switches and rheostats are a bit “jumpy” and could benefit from cleaning. A Google search revealed a number of user notes and YouTube instruction videos -- very helpful. A complete manual is available on-line. This manual is very complete -- in typical, old HP style! Unit powered on as expected, meter functioned properly, controls turned freely, but rotary switches and rheostats need to be cleaned - i.e. controls are noisy when rotated. In general, the unit appeared to function as expected…To check operation the following procedure was followed... A signal generator was used to provide a clean 1 KHz signal, 3 volts rms. The internal reference signal was adjusted properly. A sharp null was observed when unit was tuned to the input frequency. The balance controls, though noisy, were able to null properly. The measured distortion was about 0.15%. This seemed reasonable. Although the unit appears to operate properly, no effort was made to calibrate or to recondition the unit. The AWA museum does not have the staff to recondition the equipment it lists on ebay, so all items are sold in the condition they were received. Please, no returns. If a buyer is looking for a new equipment warranty, a museum is not the place to shop! If the buyer has any issue with the item as received, please contact the AWA_Museum_Store via the ebay messages BEFORE asking for a return under the eBay guarantee program. Thank you for supporting the Antique Wireless Museum with your purchase. In summary, This audio distortion analyzer, once restored and calibrated, will make good addition to any collector’s audio workbench. It is always a joy to use HP test equipment. ------------------------- Items being sold have been donated to the Antique Wireless Association Museum for improvement of its collection, or for its continuing operation and support. All proceeds from items sold go to support the Museum. The museum is chartered by the State of New York Education Department and is designated a 501c(3) not for profit organization by the IRS. Any items listed on ebay are NOT part of the Museum's accessioned collection, but are duplicates to items already in the collection, items that have been de-accessioned by the Accession Committee, or items outside the scope of the Museum's mission statement. Unless specifically stated in the item listing, items are offered in "AS-IS" condition, as donated to us. The Museum has a small staff composed entirely of volunteers and are not able to individually test each item. However any defects that can be discovered by a visual examination will be noted and described in the listing. Please ask questions well in advance of the items end time. Depending on the nature of the question, it may be forwarded to a Museum staff member with particular expertise with the item being offered. It may take up to 48 hours to respond to questions, but every effort will be made to answer as quickly as possible. Work days at the Museum are Tuesday of each week. Any items purchased will be shipped on Tuesday. Depending on staffing and volume on any given Tuesday, items purchased after 11:59PM on Monday, may be shipped the following week. If an item is needed immediately, please contact us via ebay messaging, PRIOR to bidding or purchase, and we will let you know if we can accommodate your needs. Any item purchased may be picked up in person at the Museum in Bloomfield, NY on Tuesdays between the hours of 10:00AM till 3:00PM. Please notify us in advance if you are planning on picking up the item in person so it is not packaged for shipment. Items picked up in person will have to be paid for in advance via PayPal. Terms and Conditions Shipping Unless other arrangements are made, we prefer to ship via USPS. Choice of media mail or Priority Mail Flat Rate shipping on books. Parcel Select or Priority Mail on larger heavier items. We generally ship on TUESDAY of each week, for items that we have received cleared payment by Monday at 11:59PM. If an item is specified as having Free Shipping, it applies only within the continental United States. International shipping is via USPS Priority Mail International (preferred). We are pleased to combine shipping on multiple items purchased at the same time. Please contact us or wait to be invoiced before submitting payment so that we can have a correct total for you. Multiple items shipped at the same time, offered with Free Shipping, may or may not be packaged in the same box or envelope, depending on the items size and weight. If this presents a problem for you, please email us immediately upon winning of multiple lots and we will make every effort to accommodate your needs. Please contact seller if alternate shipping arrangements are desired. Returns We do not accept returns. The only exception is if the item is substantially not as described in accordance with ebay policy. WE make every effort to be accurate in our descriptions and photos to fairly depict the condition of the items. Vintage electronics are not returnable due to the age and nature of the item. All items are shipped insured for full value of the final price and we will cooperate fully in providing necessary paperwork or information required in the filing of any claim for damage during shipping. Packaging We package items well, with adequate space for cushioning, using the correct size bubble wrap for the size and weight of the item and Styrofoam peanuts on all sides. Electronics are packaged with at least 2-3 inches of space for peanuts or cushioning material on all sides after the item is bubble wrapped. Books are bubble wrapped when shipped in boxes or shipped in cushioned envelopes depending on size, weight and whether being shipped by Media or Priority Mail. International Bidders We welcome bidders worldwide. International shipping is via USPS Priority Mail International -- preferred. Please be aware that we will not alter customs forms to reflect lower values or label merchandise as gifts. Buyer is responsible for any and all duties or taxes applicable in their countries. If there are any questions regarding any of the above, please contact us BEFORE submitting a bid. To All Customers We appreciate your interest in our items. Enjoy trading on ebay. We will do everything we can to make every transaction smooth and pleasant for everyone.
By clicking "Accept All Cookies", you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts.
