GROUP OF EIGHT (8) RARE SILVERTONE 45A VACUUM TUBES SPECIAL 45 DOUBLE TESTED AMPLITREX WESTMORE
PLEASE READ MY TERMS AND CONDITIONS CAREFULLY!
LOT DETAILS This sale is for a group of 8 Silvertone 45A vacuum tubes. They do not often come up for sale, and almost never in groups such as this one. It took me a long time to assemble this group, but I am never going to use them so it is time to pass them on. The 45A is a rare uprated 45 variant. My understanding is that the max plate voltage is increased from 275 to 325 Volt, and the power output is increased from 1.6 (at Vp=250V and grid bias -50V) to 3 Watts (at unknown conditions). All 8 tubes have engraved bases. Tubes #1-5 have a date code of 49AX, tubes #6-7 have a date code of 49X, and tube #8 has a date code of 4CX. All 8 tubes appear to have an identical structure, except that tubes #1-7 have a button style getter element, while tube #8 has a flat plate with dimple style getter element. I cannot find a data sheet for the 45A, so I do not know the best test conditions. As a result, I tested them as a normal 45 on a couple of different testers. I first tested these on my Westmore 501 (gov’t version of Triplett 3444) connected to a regulated power supply. My experience is that the Westmore is very effective for testing directly heated triodes (DHTs). Indicated test parameters for a 45 are 250 Vp and -45V grid bias. I tested for both transconductance (Gm) and current draw. On the Westmore, the Gm reject point is 1100 micromhos and average new is 2200 micromhos. While there is no Westmore spec for plate current, the Class A plate current spec for a 45 at 250 Vp and 50 V grid bias is 34 mA. The results are as follows (Gm/current draw): Tube #1 2400/37 Tube #2 2100/32 Tube #3 2050/34 Tube #4 1700/28 Tube #5 1700/28 Tube #6 2300/36 Tube #7 1750/31 Tube #8 2400/36 All tubes were clean for shorts, leakage and gas on the Westmore. I then tested these on an Amplitrex AT-1000 connected to a regulated power supply. The tubes were tested in fixed bias mode. I ran the test cycle at least twice for better warmup and stabilization, and the test results are from the last cycle. The test conditions are Vp=275V and grid bias of -54.8V. For a normal 45, spec transconductance (Gm) on the AT-1000 is 2.0 mA/V, and emission (current draw) is 36.0 mA. The test results are as follows (Gm/current draw): Tube #1 2.24/35.8 Tube #2 1.45/21.3 Tube #3 1.66/27.2 Tube #4 1.24/19.2 Tube #5 1.24/17.8 Tube #6 1.56/25.2 Tube #7 1.08/18.2 Tube #8 2.13/31.2 The tubes were clean for shorts and leakage, and only registered a normal amount of grid emission (very little, indicating no gas issue). You will notice that the test results are significantly different on the two tube testers. The Westmore pushes the tubes a little harder, so that may be why the Westmore results look better as the 45A should require a little more effort than the 45 to achieve its design power output. I do not know which test results are most representative – please judge for yourself. In any event, these tubes should be considered USED for the purposes of this sale.
ADDITIONAL TERMS AND CONDITIONS The buyer is responsible for all shipping charges (including but not limited to any customs fees, duties, import taxes and related charges). I WILL NOT FALSIFY INFORMATION ON A CUSTOMS FORM. All shipping will be via USPS Priority Mail unless otherwise requested. For all shipping, the terms are EXW US Post Office (INCOTERMS 2010). In accordance with these terms, I will deliver the lot into the possession of the US Post Office, and once in the possession of the US Post Office ALL RISK OF LOSS PASSES TO THE BUYER. WHAT THIS MEANS IS THAT I EXPRESSLY DISCLAIM ANY AND ALL RESPONSIBILITY FOR DELIVERY (INCLUDING BUT NOT LIMITED TO DAMAGE OR LOSS) BY ANY POSTAL SYSTEM, AND BY PURCHASING THIS LOT YOU EXPRESSLY WAIVE THE RIGHT TO FILE A CLAIM (INCLUDING BUT NOT LIMITED TO BUYER PROTECTION CLAIMS WITH PAYPAL) FOR ANY SHIPPING RELATED ISSUE. If, however, you have purchased insurance for the item, I will assist to the best of my ability in the processing of any legitimate insurance claim you desire to file. For payment, I accept Paypal (no fee strongly preferred). Money Orders and personal checks are also OK, but those must clear my bank first. I might consider some trade, but it has to be for the right value. While I have no specific needs, it does not hurt to ask. In addition, to avoid any misunderstanding, the following applies: THIS LOT IS BEING SOLD “AS IS, WHERE IS” AND “FOR PARTS/REPAIR.” THERE ARE NO REPRESENTATIONS, GUARANTEES OR WARRANTIES ON THIS LOT, AND THERE ARE NO REFUNDS OR RETURNS. THE BUYER ASSUMES ALL RISK IN PURCHASING THIS LOT. I ONLY describe what I know about the tubes, and what I have tested for. I may provide test results and, while my tube testers tend to be reliable, YOUR TUBE TESTER MAY GIVE A DIFFERENT RESULT THAN MINE, so please take that into account. In the event of a tube tester conflict, MY TUBE TESTER CONTROLS. AS SUCH, PLEASE NOTE THAT I CANNOT GUARANTEE (OR EVEN REMOTELY PREDICT) HOW THESE TUBES WILL SOUND OR PERFORM IN YOUR EQUIPMENT. ANY TEST RESULTS ARE ONLY PROVIDED AS AN INDICATION OF TUBE PERFORMANCE IN A VERY LIMITED (AND NON-IDEAL) ENVIRONMENT. EXCEPT AS EXPRESSLY INDICATED IN THIS LISTING, I DISCLAIM ANY AND ALL REPRESENTATIONS, WARRANTIES AND LIABILITY WITH RESPECT TO THESE TUBES, OR RESPONSIBILITY FOR YOUR USE OF THEM. By purchasing this lot, you acknowledge that you have read and understood this entire listing, including all my terms and conditions, and agree to accept and abide by those terms and conditions. Please take all of this information into account when purchasing.
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