We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: Talking House transmitter audio upgrade  (Read 2581 times)

Offline ChrisSmolinski

  • Administrator
  • Marconi Class DXer
  • *****
  • Posts: 31106
  • Westminster, MD USA
    • View Profile
    • Black Cat Systems
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
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline Dave Richards

  • Jr. Member
  • **
  • Posts: 96
  • Oakland, CA
    • View Profile
    • Ham Radio (and occasionally Part 15) Blog
    • Email
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!
Oakland, CA
(SF Bay Area)

Offline N0TLD

  • Jr. Member
  • **
  • Posts: 24
  • somewhere in the Ozarks
    • View Profile
    • Email
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
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, Hallicrafters S38 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

  • Administrator
  • Marconi Class DXer
  • *****
  • Posts: 31106
  • Westminster, MD USA
    • View Profile
    • Black Cat Systems
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 Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline N0TLD

  • Jr. Member
  • **
  • Posts: 24
  • somewhere in the Ozarks
    • View Profile
    • Email
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, Hallicrafters S38 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 ThaDood

  • DX Legend
  • ******
  • Posts: 1209
  • Likely, not where you are.
    • View Profile
    • Extreme Part #15!
    • Email
Re: Talking House transmitter audio upgrade? Youtube VID and thread!
« Reply #5 on: September 08, 2020, 1808 UTC »
Yeah, really nice Youtube VID on how to stop audio distortion above 2kHz and to improve the auto-tuner. But, what I wanna' know is where did this guy get the schematic for the I Am Radio / Talking House transmitter? I've been wanting that for years. And, of course he's using a nice 100MHz o'scope and what was a $15k Orban optimod.         https://www.youtube.com/watch?v=7mSZn5cPX5E&feature=youtu.be
UPDATE: Boomer just linked me into the thread for that here,     https://antiqueradios.com/forums/viewtopic.php?f=12&t=131621
« Last Edit: September 09, 2020, 1812 UTC by ThaDood »
I was asked, yet another weird question, of how I would like to be buried, when I finally bite the big one. The answer was actually pretty easy. Face-down, like a certain historical figure in the late 1980's, (I will not mention who, but some of you will get it, and that's enough.) Why??? It would be a burial that will satisfy everyone: (1) My enemies will say that it will show me where to go. (2) On the same point, I can have my enemies kiss my butt. (3) It will temporarily give someone a place to park a bicycle. See??? A WIN / WIN for everyone.

 

HFUnderground Mug
HFUnderground Mug
by MitchellTimeDesigns