For sale a 27SU half wave HT rectifier valve / vacuum tube by Cossor, new old stock and recently tested at 100% of nominal new emission. This particular example has all original markings present and correct and is still in its original Cossor box - also in very good condition.
The 27SU is on a standard 8 pin IO base and dates from the late 1930s / early 1940s. It is intended for use in reasonably sized domestic equipment or even early AC/DC television sets, having a rather rare 13.25V @ 0.9A or 26.5V @ 0.45A heater rating. It will deliver a maximum DC output of 250mA at 250 volts and is actually two rectifiers in the same envelope, strapped in parallel. Hence the availability of the series or parallel heater arrangement. Nowadays, you can power the heater from a 12 (parallel) or 24 (series) volt transformer with a couple of overwinds, or from a car battery (or charger).
Don't believe the confusion that exists on line over heater ratings for this valve. This is the CORRECT data.
Fully tested on my Mullard High Speed Valve Tester and showing zero faults and 100% of nominal new emission. A reasonable price for this fully working quality example of a now rare old valve/tube. Ideal for vintage equipment restorers, experimenters, collectors alike.
27SU
Heater = 13.25V @ 0.9A and 26.5V @ 0.45A
Diode:
Anode / Plate: 250V max / 250mA continuous
I offer a full, money back guarantee if you are not completely satisfied with this purchase (see terms). We have been trading since 1927 so bid with confidence. Most of our valves / tubes have been in our own stock room for many, many years. See our EXCELLENT FEEDBACK on quality valves / tubes previously supplied!
We have thousands of valves / tubes in stock - standard and rare; US, UK and European. If you have any particular requirements, please send a message and if we have what you want, we will list it here.
We ship worldwide and are very happy to combine items for multiple postage.
TERMS
GUARANTEE: In case of dissatisfaction, buyer must return item at own expense. We will only refund if you return the EXACT SAME VALVE / TUBE to us that you have purchased, with the heater still intact and passing continuity test. Believe it or not, some evil people have tried to send us back their dud tubes to try and get a full refund for a perfectly good tube we have just sold them! So, refund is a genuine offer, but at our discretion that we have been sent back what we actually sold you in the first place and that you haven't destroyed it through misuse! All returns under guarantee are limited to within 21 days of shipping.
PAYMENT: We accept all usual eBay payment methods. We are happy for you to collect from Bristol, but will require payment in GBP CASH on collection.