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Author Topic: Talking House transmitter audio upgrade  (Read 480 times)

Offline ChrisSmolinski

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Talking House transmitter audio upgrade
« on: May 16, 2020, 1123 UTC »
I was rather annoyed with the poor bass response of the TH transmitter (Rev 4.6). OK, poor is an understatement, pretty much everything below 700 Hz or so was missing. I ended up putting a non polarized 1 uF capacitor in parallel with C301 (located near the center of the PCB, it's a green capacitor) which improved the bass response down to around 40 Hz. I also put an equalizer in the audio chain, to help boost the bass a bit more.   Thanks to Dave Richards for pointing me in the right direction.
Chris Smolinski
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Offline Dave Richards

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Re: Talking House transmitter audio upgrade
« Reply #1 on: May 16, 2020, 1615 UTC »
Glad you were able to improve the bass response somewhat Chris. I suppose that, given the original intended purpose of these units, we shouldn't be expecting too much in the way of quality audio from them. I have never used one, but picking up a used TH seems like it might be a good way to dabble in Part 15 without breaking the bank. I nearly fell off my chair when I first discovered the price of a Rangemaster!
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Offline N0TLD

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Re: Talking House transmitter audio upgrade
« Reply #2 on: June 10, 2020, 1958 UTC »
I use a TH transmitter around the homestead and have always felt the bass was weak, so I am grateful you posted your improvement. Just for clarification, by non-polarized, you mean a non-polar (or 'bipolar') electrolytic type, right? Or could one use a common ceramic (or mica or mylar, etc.) fixed, non-polarized type?

Mike
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Kenwood TS940s/at; Kenwood TS450s/at; modified Icom R75; modified Sony ICF2010; Panasonic RF2200, RF2600, RF2800, RF2900; Zenith Trans-Oceanic R-7000-2; numerous other vintage multi band receivers; Silvertone 4565, Grundig 2440U and numerous other vintage tube radios; numerous homebrew crystal sets; numerous homebrew long/randomwires and loops including a 290' Loop On Ground with a homebrew 9:1 transformer; Par EF/SWL sloper; Wellbrook ALA330 and ALA1530LNP loops; 5/8 ground plane vertical.

Offline ChrisSmolinski

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Re: Talking House transmitter audio upgrade
« Reply #3 on: June 10, 2020, 2157 UTC »
I use a TH transmitter around the homestead and have always felt the bass was weak, so I am grateful you posted your improvement. Just for clarification, by non-polarized, you mean a non-polar (or 'bipolar') electrolytic type, right? Or could one use a common ceramic (or mica or mylar, etc.) fixed, non-polarized type?

Mike
N0TLD

Correct.  Not sure what type I used, it was found in one of my junk boxes  :)
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 120 ft T2FD/ 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline N0TLD

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Re: Talking House transmitter audio upgrade
« Reply #4 on: June 11, 2020, 0422 UTC »
Oh yes, I'm sure I have something usable in the MANY junk boxes around here as well! :) Thanks for the clarification.


Mike
N0TLD
Kenwood TS940s/at; Kenwood TS450s/at; modified Icom R75; modified Sony ICF2010; Panasonic RF2200, RF2600, RF2800, RF2900; Zenith Trans-Oceanic R-7000-2; numerous other vintage multi band receivers; Silvertone 4565, Grundig 2440U and numerous other vintage tube radios; numerous homebrew crystal sets; numerous homebrew long/randomwires and loops including a 290' Loop On Ground with a homebrew 9:1 transformer; Par EF/SWL sloper; Wellbrook ALA330 and ALA1530LNP loops; 5/8 ground plane vertical.