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Hey all, I am completely new to this website/forum and I am new to the "Talking House" AM Transmitters. I picked this one up last week at a garage sale for only $8 (talked them down from $10). I can't seem to find anything on it...it works ok and came with the wire antenna, but I'm curious about the controls (unmarked 4 position switch) and what kind (if any) auxillary input can I use? Is the aux input on the back just a microphone jack, or can I hook a cd/dvd player to it for non-loop use? Any help would be greatly appreciated! Thanks!
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Low Power is better than No Power...
What Talking House model do you have? I don't recall an unmarked switch on mine (which is one of the later ones with a 5 minute message stored digitally).
The aux input would be a line level input, suitable for a CD player, computer sound card, etc. Mine is a mono RCA jack.
You want to get that wire up as high as possible, preferably outside, as any obstructions will reduce your signal strength and reduce range. I ran mine inside a length of PVC pipe, and put the Talking House on a shelf high on the wall, running the wire through the wall. The PVC pipe was mounted on the eve of the house and the top of the wire almost got to the roofline (I live in a one story house). The necessary ground is supplied by the OEM AC adapter (the chassis is grounded to the neutral, I believe). So you don't want to switch adapters.
You might want to consider a ground isolation transformer on the audio line to the transmitter - it reduces hum. There's nothing you can do about the hum introduced by the cheap wall wart they give you, unless....
[The following appears to be controversial on this Forum. Be prepared to get lots of comments.]
you use a Talking House ATU, which the device is CURRENTLY FCC certified with under Part 15 rules. The ATU is mounted outside and is supplied with coax which you run from the Talking House to the ATU (I would use what is supplied by the manufacturer with the ATU to ensure that you stay within certification). You attach a whip antenna to the ATU, and a ground wire, as long as the total length of the whip plus the ground stays under 3 meters in length, as specified in Part 15 rules. You're safest (at least with regard to legality) with ground mounting the ATU, and running the ground wire to a ground rod pounded into the earth or some other suitable ground. There have been many discussions on this Forum about legal installations, legal grounding, etc. and you should probably research those if you go the ATU route.
If you use the ATU with a proper ground, you can get rid of that Talking House wall wart and use a well regulated 13.8 volt supply to the transmitter (others have reported that it will operate with as low as 12 volts). I managed to almost completely eliminate hum in that manner.
Another improvement you can consider once you're looking for something else to do is to add radials running along the ground from your ground rod. Again, there have been lots of suggestions and discussion about using radials here (numbers required, length of each radial, using insulated wire vs bare wire) - my suggestion is to read and then experiment. Theory and someone else's experience is one thing, YOUR reality something else.
At the end of the day, we're dealing with such miniscule signal levels in Part 15 that local factors probably have more of an influence on your results than anything else. What is the geography, how many and type of obstructions, type of soil and it's suitability as a ground, local interference, even what you're broadcasting (thumping rock music vs delicate classical music as an example) etc. etc. Listen, research and then try things out.
Here on this forum alone must be 100 or so discussion messages, and more reviews around the web such as:
http://antiqueradios.com/forums/viewtopic.php?t=131621
http://www.hobbybroadcaster.net/reviews/Talking_House_P01.html
I also have never seen a TH AM tx with an unmarked 4-position switch (I have 3 of them)... must be some sort of mod.
Does yours look like a dvd player? I seem to recall the very first version did not have that look, was smaller, and may not have had the patented tuning system.
Audio in early models, before v.5, had narrow audio bandwidth for voice-only because their targeted market was real estate sales; consequently music sounds flat and tinny unless you modify the circuitry.
Both of my operational units have separate inputs for mic (one was available) mainly for recording to the onboard storage IIRC, or line for external sound source.
Mine also have switched antenna outputs for either the supplied 3-meter wire (normally do not change the length of that) or the external ATU previously mentioned which uses an F-type tv cable connector.
Good advice by both AR and Ken. However there never was any question regarding the ATU being certified. Again, there NEVER was any question about the ATU being certified.
There IS a question on why the certification documents are missing and RS refuses to provide a copy. THAT is what is in question AND exactly how the ATU was mounted for certification. The documents will have photos showing this setup. But as noted, they seem to be misplaced or purged or sitting in a confidential file drawer being carefully watched. Why is a good question in of itself, but does not matter. Other powers will pry them out of that file drawer if they want to or not.
The instruction manual suggests mounting along side a wall of the house, or on a short pole. Most agree that it was probably set up in this manner during the testing for certification.
In other words, think of the typical real estate sales situation. A for sale sign out in the front yard of a house, which stands about 1 meter tall, and the ATU is mounted onto the for sale sign and the coax ran along the ground into the house where the transmitter is located.
This is also how ALL Part 15 devices that emit intentional radiation are tested..they are placed onto a metal table 1 meter tall, and connected to a ground plane system in the testing room, and the device being tested is placed onto the table, or mounted onto a very short stub which is also on the table, then the ground connected to this table, or a wire ran from the ground slug of the ATU or other device to the ground plane below the table. Then the device is tested.
The "debate" of the ATU is this. It is seriously doubted that the FCC and OET approved these devices for use with the ATU mounted up in the air beyond 1 meter of the ground. I doubt they would gripe if it was 2 meters, perhaps even 3. But going up 6 meters or more...I am sure that was not part of the "real estate sales" concept nor do any of the testing procedures outlined by the OET allows for devices or ATU's to be tested while sitting 20 + feet up in the air on a pole.
Anyway, use your good judgement and keep tabs here at Part 15.us for updates on the missing OET data. The process is well underway.
Good luck!
RFB
The 4 position switch is the one that switches from the "record" to "play" functions. The record function is at the far right, the play is at far left. There are two more positions between, and I don't know what they do...also it's the pic with my profile...I think it might be a TH 2? I was just wondering how I set it up to not use the "loop" and input only through the aux jack..?
I have been told it's either a TH 2 or a TH 3...I'm just needing a way to not use the "loop" function and yet still transmit...also, there is no way to change the power supply...it is a hard-wired AC 3 prong plug that, upon opening the unit, has a transformer inside and rectified DC power supply...not sure of the voltage, hadn't checked it yet for exact voltage...
I have been told it's either a TH 2 or a TH 3...I'm just needing a way to not use the "loop" function and yet still transmit...also, there is no way to change the power supply...it is a hard-wired AC 3 prong plug that, upon opening the unit, has a transformer inside and rectified DC power supply...not sure of the voltage, hadn't checked it yet for exact voltage...
That's definitely one of the early ones.
I've never used one of those, maybe someone here has.
I guess you have no choice in what you use for power, if the power supply is inside the unit.
And my guess would also be that plugging something into the Aux Input would automatically switch to transmitting that, as opposed to the loop. Some Talking Houses have an explicit switch for that; mine (and I have two) both automatically transmit the Aux signal.
I appreciate it. I saw on this board somewhere that this is one of the ones I don't want, but for under $10, I couldn't resist. It seems to work ok, I have recorded a short test message, but range is only a few hundred feet with the supplied wire "antenna..." I may try to build an sloper, inverted "v" or something of the sort...also, I don't have any antenna jack other than the screw for hooking the wire antenna to...I wonder is it a TH 1 or 2 or 3??? It has the digital voice loop in it...
The picture you posted is one of the very early units unlike the Talking House most use. I believe yours is not a PLL controlled transmitter although it may have a digital frequency display. Is the transmit frequency adjusted with a rotary control?
I have several TH II transmitters. None has a 4 position slide switch for record/play. Rather, there are buttons on the front, either side of the frequency up/down buttons, for PLAY and RECORD.
There is a small push button on the back next to the CONTROL LOCK which is a RECORD PAUSE.
The only slide switches are for remote antenna select (YES/NO) and message select (1/2).
The only rotary control is the speaker volume control.
The "loop" message would shut off when you insert a plug into the live input feed jack if yours was one of the "DVD" style in appearance units.
Mine has a rotary control for frequency (522 KHz to 1633)...it is a digital readout though...only thing on the back is aux input and antenna screw (and line in for 120 VAC)...there is a switch to turn the speaker on/off and the 4 position slide switch I already mentioned...and the frequency control we mentioned too...I am hanging an antenna this afternoon later and I will try to hook an mp3 player to it and see if the loop stops or not...thanks!
Might I suggest that you post a few pictures of this mystery unit. Perhaps that might help with identifying the thing.
And get a good picture of the label..the one that shows the model number and the FCC ID number.
RFB
You can view pictures of the transmitter on the blog I started at
http://www.part15.us/node/3912
You can also reply/respond there with any tips/help...thanks and sorry for the poor quality of the pictures...
Dave KA0VQX
I would just like to say thanks for all of the input/comments/encouragement/ideas/comments/mods/comments and did I mention comments about the TH-??? that I obtained. This forum and the blog have been the most helpful in my quest of experimentation on a little-known-to-me corner of the AM Broadcast spectrum. Thanks again, and hopefully, I can help you all as much as you have helped me...
Dave KA0VQX