[GreenKeys] TU filters for 170hz shift...

[Jack]

Ken,

 

Those old pre-tuned filters were usually 600 Ohms in and out. You’d need to modify

that TU for the low impedance (usually a cathode follower stage). I had

a box full of UTC tone filters that I used for multiple TU projects

over the years. The 2125, 2295 and 2975 filters are long gone.

 

Jack

 

 

 

From: greenkeys-bounces at mailman.qth.net [mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of Kenneth Gartland
Sent: Monday, October 23, 2017 5:03 PM
To: greenkeys <GreenKeys at mailman.qth.net>
Subject: [GreenKeys] TU filters for 170hz shift...

 

Hi all!

 

My thanks to Jack, Ralph and all, for the info and

suggestions for the filter issue(s) of the older

slug tuned filters used in the early vacuum tube

T.U.s...

 

Are there "Off the shelf" type fixed audio filters

available for the two frequencies used for 170hz?

 

I remember years back, I had a set of factory tuned

filters from a 43A carrier set which I am sure were

tuned for 2125 and 2975hz respectively used

back in the 850hz days...

 

They worked great and were rock solid, it was

so long ago, I am sure no one has any of these

filter units anymore...

 

If anyone knows if pre-tuned filters are available

from a supplier, wud appreciate the info!

 

Many thanks!

 

73'

 

Ken

VE3-HMQ

i-Telex 61663

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