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Author Topic: Spitfire Am transmitter  (Read 2126 times)

Offline chanito

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Re: Spitfire Am transmitter
« Reply #15 on: February 22, 2020, 0306 UTC »
I got the Spitfire. With the provided 9' antenna wire it is piss poor. Not even good to 16 feet. POS. Won't go from 2nd fl to 1st fl in a house. Looking for an alternative.
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Offline redhat

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Re: Spitfire Am transmitter
« Reply #16 on: February 22, 2020, 0328 UTC »
Does the provided antenna have a loading coil or is it just a wire with a connector on the end?

+-RH
Somewhere under the stars...
WinRadio Excalibur/305 w/ a chi-town resonant loop, Kenwood KDC-U356 for mobile listening.
Please send QSL's and reception reports to xfmshortwave [at] gmail [d0t] com

Offline chanito

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Re: Spitfire Am transmitter
« Reply #17 on: February 22, 2020, 0354 UTC »
Does the provided antenna have a loading coil or is it just a wire with a connector on the end?

+-RH


9' wire with RCA connector.
PCR-1000, PCR-1500, RSP1A, RSP1, VR-120D, HDT-1, Accurian HD, Royal 3000
Caras HF-315, Belar LP-1A, SuperAntenna MP-1, RatShack 20-043 discone, MLA-30, 100' wire

Offline redhat

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Re: Spitfire Am transmitter
« Reply #18 on: February 22, 2020, 1408 UTC »
That's why it sucks.  You need to build a tuned antenna for something that short.  Something like this...



To add insult to injury, anything in you house that radiates will get into the powerline, and cause apparent hum in your signal.  Its actually RF getting into all the rectifiers in every switching supply in the house and through nonlinear mixing, superimposing 120Hz on the signal and re-radiating it.  The transmit antenna should really be outside if you want to be able to listen to it.

+-RH
Somewhere under the stars...
WinRadio Excalibur/305 w/ a chi-town resonant loop, Kenwood KDC-U356 for mobile listening.
Please send QSL's and reception reports to xfmshortwave [at] gmail [d0t] com

Offline ChrisSmolinski

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Re: Spitfire Am transmitter
« Reply #19 on: February 22, 2020, 1645 UTC »
The Talking House transmitter actually has a built in antenna tuner. You can hear the motor adjust the ferrite core as it tunes when you change frequency. A bit complicated, but certainly the best way to squeeze out every foot of range from a legal Part 15 transmitter installation.

I have a Talking House transmitter for sale BTW if anyone is interested. Almost new in box except for me taking it out a few times to play with it  :)
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 / 300 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline chanito

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Re: Spitfire Am transmitter
« Reply #20 on: February 22, 2020, 2242 UTC »
I got it cookin' now. It's running with internal ATU OFF, into a 9:1 balun and a respectable piece of wire length. Now to condense that wire down to a "load".



PCR-1000, PCR-1500, RSP1A, RSP1, VR-120D, HDT-1, Accurian HD, Royal 3000
Caras HF-315, Belar LP-1A, SuperAntenna MP-1, RatShack 20-043 discone, MLA-30, 100' wire

Offline chanito

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Re: Spitfire Am transmitter
« Reply #21 on: February 22, 2020, 2245 UTC »
The Talking House transmitter actually has a built in antenna tuner. You can hear the motor adjust the ferrite core as it tunes when you change frequency. A bit complicated, but certainly the best way to squeeze out every foot of range from a legal Part 15 transmitter installation.

I have a Talking House transmitter for sale BTW if anyone is interested. Almost new in box except for me taking it out a few times to play with it  :)


I would really like to know how the TH & Range Extender setup works. Is it really a signal directly from the TH to the Extender tuner section? OR a low level signal that is then amplified by the Extender? OR, is it just audio and power down the coax with a bias tee on the Extender and a transmitter integrated there.


How did TH get FCC certification using a variable coax length?


 
PCR-1000, PCR-1500, RSP1A, RSP1, VR-120D, HDT-1, Accurian HD, Royal 3000
Caras HF-315, Belar LP-1A, SuperAntenna MP-1, RatShack 20-043 discone, MLA-30, 100' wire

Offline NJQA

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Re: Spitfire Am transmitter
« Reply #22 on: February 23, 2020, 1300 UTC »
As I remember, the amplifier and matching network are out at the antenna.  The coax merely brings a low level RF signal from the indoor unit to the outside amplifier.  So rather than put everything in one box, they split it into two.



Offline NJQA

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Re: Spitfire Am transmitter
« Reply #23 on: February 23, 2020, 1314 UTC »
Outdoor unit:

http://talkinghouse.com/range-extender-2.5.htm

https://www.hobbybroadcaster.net/reviews/iss-range-extender-2.5-talking-house-iam-radio.php

The antenna tuner in the outside unit looks a lot like that used in the inside unit (https://images.app.goo.gl/BMwyMH8ZS4LTTBT99).

I donít know if they actually put the final amplifier outside or not.

Note the patent links on this page.  They provide an explanation of how it works.

http://www.prc68.com/I/TalkingHouseTransmitter.html

« Last Edit: February 23, 2020, 1324 UTC by NJQA »

Offline ChrisSmolinski

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Re: Spitfire Am transmitter
« Reply #24 on: February 23, 2020, 1652 UTC »
How did TH get FCC certification using a variable coax length?

I am not sure how they got the basic unit certified, since the ground connection turns the ground wiring in your entire building effectively into part of the antenna.
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 / 300 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline chanito

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Re: Spitfire Am transmitter
« Reply #25 on: February 23, 2020, 2245 UTC »
Property coverage achieved. Sounds pretty good driving it with a cheap Chinese mini PC running RadioDJ, into a Behringer Composer Pro-XL.
PCR-1000, PCR-1500, RSP1A, RSP1, VR-120D, HDT-1, Accurian HD, Royal 3000
Caras HF-315, Belar LP-1A, SuperAntenna MP-1, RatShack 20-043 discone, MLA-30, 100' wire

Offline redhat

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Re: Spitfire Am transmitter
« Reply #26 on: February 24, 2020, 0503 UTC »
I got stereotool to run on a pi4 and a hifiberry card last weekend.  Uses 1/3 the dc of my current processor, sounds good too 😊

+-RH
Somewhere under the stars...
WinRadio Excalibur/305 w/ a chi-town resonant loop, Kenwood KDC-U356 for mobile listening.
Please send QSL's and reception reports to xfmshortwave [at] gmail [d0t] com

Offline chanito

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Re: Spitfire Am transmitter
« Reply #27 on: February 25, 2020, 0156 UTC »
Think I'll try StereoTool to see if it is better than the spartan integrated processing in RadioDJ. I'm only using the AGC control there and passing the peak limiting to the Behringer.


An aside...


Why do we want to transmit AM to our yard and home?


Well, for me, it's something odd. I have a veritable plethora of 70's music of all genres. A lot comes from the inevitable Time/Life series. In fact, I have a "TL" format on RadioDJ for this AM station. All Time/Life, all the time. Why???


All of this music, for me, was listened to via AM radio. During the majority of the 70's I was in an area that wasn't served by any listenable FM station, so everything was AM Top 40 from local and at night, distant stations.  I have a certain affinity for the sound of AM radio. That's it. Carole King or Jethro Tull hit music sounds weird in pristine, clear, digital audio. I know it from AM. And I like it that way.
PCR-1000, PCR-1500, RSP1A, RSP1, VR-120D, HDT-1, Accurian HD, Royal 3000
Caras HF-315, Belar LP-1A, SuperAntenna MP-1, RatShack 20-043 discone, MLA-30, 100' wire

Offline ChrisSmolinski

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Re: Spitfire Am transmitter
« Reply #28 on: February 25, 2020, 1131 UTC »
All of this music, for me, was listened to via AM radio. During the majority of the 70's I was in an area that wasn't served by any listenable FM station, so everything was AM Top 40 from local and at night, distant stations.  I have a certain affinity for the sound of AM radio. That's it. Carole King or Jethro Tull hit music sounds weird in pristine, clear, digital audio. I know it from AM. And I like it that way.

I recall hearing The Doors "Riders On The Storm" on a MW pirate out of NYC just above the broadcast band (1620 ish) back in the 80s, with static and fading. It's a memorable sound.
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 / 300 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline chanito

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Re: Spitfire Am transmitter
« Reply #29 on: March 03, 2020, 0213 UTC »
Swapped Behringer out for a Aphex 320A Compellor. Much better.
PCR-1000, PCR-1500, RSP1A, RSP1, VR-120D, HDT-1, Accurian HD, Royal 3000
Caras HF-315, Belar LP-1A, SuperAntenna MP-1, RatShack 20-043 discone, MLA-30, 100' wire