You have not mentioned the most important part...
Re-wiring the 120 volt cut off bias. If a tube shorts, it takes out the
filament transformer.
Study the schematic.
Thanks
73
Jim W7RY
On 4/29/2019 7:52 PM, Artek Manuals wrote:
OK after a bit of sleuthing and help from the A/C repair guy next door
who has a meter that measured the airflow I found two probable exact
replacements for the fan in the TL-922A... Which suggested that this
was an ~53CFM fan that originally was spec'd at 100V/7W probably
1700RPM. Size: 120mm x 120mm x 38mm
The first from Mouser is a Sanyo Denki fan #109S006 a very quiet fan
at 28dBa. Problem is that it is a non stocked item with a minimum
order quantity 40pcs at $24.76 ( extended order price of $990 !) ...
deal breaker for sure
With the spec sheet for the Sanyo in hand I could now look for other
equivalents ! . I found the following on Amazon.
"AC Infinity LS1238", 62 CFM @32dba 120V/8W (probably 7W at 100V).
$14.99 free overnight delivery ...Bingo
Easy replacement. The new fan though rated at 62CFM measured closer to
55CFM installed in the amp. The old fan would raise the noise level at
the operating position when switched on by approximately 12dba as
measured with two different phone apps. The new fan switched on raised
the noise level by only 2db when switched on a big improvement over
the old worn out one. Air exit temperature was identical to the old
fan at around 30C at idle and 35C key down for 2 minutes.
So TL-922 owners print this info out and store it with your manual
Tomorrow I will detail the rest of the TL-922A makeover, new tube
sockets, new band switch, new tubes and a W8JI grid grounding party
Cheers
Dave
NR1DX
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