- February 19, 2009 at 4:24 am #7222acex33Participant
Total posts : 1
I just purchased a TH-2 from eBay for $45 including shipping. It appears to be brand new and never used. Upon powering up, the display flashed between “1670” and “CAL” and the motor ran continuously for several minutes; as others have experienced. I powered down the unit and opened the case, then powered back up and watched the automatic tuner…it did not appear to be obstructed or broken, nor did it sound as if the motor was labored; it just moves a fraction of an inch, then rolls back and starts again. I powered down again and put a very small glob of white petroleum on the small white gear wheel directly underneath the motor on the automatic antenna tuner assembly, then gently but firmly forced the assembly about halfway through its range of motion inside the coil. When I powered up again, the tuner assembly smoothly rolled the rest of the way into the coil, then out again, stopping and fine-tuning at the correct frequency. You might try this before you start the hassle of trying for an eBay refund or trashing the unit.
My theory is that these are not lubricated at the factory, and/or get slightly stuck at the extreme open end of the range of motion; or it might be possible that they sometimes get jarred during shipment, causing the gearset underneath the tuner motor to become slightly unmeshed/out of sync.
Incidentally, my particular variant of the TH2 does not have a switch on the back for turning off the memory buffer and broadcasting from the live feed; but if the unit detects any input signal from the RCA jack it will automatically broadcast from the live feed and automatically switch back to the buffer when the input signal is removed.
I have read in other posts that input volume is a problem. In my case, I have a stereo to mono connector at the sound card, connected to a 1/4″ mono to RCA mono adapter, to a single RCA cable, to the unit. The input volume from my soundcard was too much and was causing distortion….about a 20% volume level is optimal to broadcast to a 1934 Philco Model 84-B and voice and music sound excellent anywhere in the house. In a car radio, the signal is faint just outside the house and vanishes at anything farther than about 20 yards.February 19, 2009 at 4:44 am #17091scwisGuest
Total posts : 45366February 20, 2009 at 12:33 am #17100mram1500Guest
Total posts : 45366
I picked up 5 used TH II’s on Ebay for $20 each. The listing stated they would not calibrate. Such was the case for 4 of the 5.
In my case, I had to disassemble the tuning mechanisms to clean and ream the plastic piece which rides on the metal rod. In one case the inside of one of the coil forms had to be carefully polished out with emery cloth as the tuning slug was dragging on it.
One of the units worked perfectly out of the box, calibrating OK and transmitting over the entire frequency range listed. The other repaired units calibrate but won’t go higher than 1680 kHz regardless of the display. Other than that they all work just fine.
I’d sure like to get my hands on a schematic!February 23, 2009 at 9:06 pm #17105rock95sevenGuest
Total posts : 45366
Just wondered, with the wire antenna included with the TalkingHouse Transmitters, what kind of range do you get?
I read on their website to expect 3000 ft ? is that the case?
I am running into a problem here with mounting my amt3000, we can probably mount it outside but grounding it would be frowned on since it would include tracing water and gas lines. Around here they charge for that information. So i am looking at other options.
I probably should have asked this question somewhere else but i thought since your on the subject. 🙂February 24, 2009 at 1:42 am #17106scwisGuest
Total posts : 45366
With my best TalkingHouse, properly loaded on the audio input with lots of ‘oomph’ in the audio content, with the wire antenna that comes with the unit held aloft by a fiberglas pole, I have definitely hit the 2,000 foot mark on a car radio. About 1,500 feet with a pocket radio, but that takes the old ‘hold the receiver up in the air and twist it around’ like we used to do in the 60s. Pretty good pattern, though.
I think pumping the audio as LOUD as possible is very helpful in kicking a bit more usable range – it seems to help a receiver accept and process the signal rather than rejecting the signal as too weak and not passing the signal along to the IF
3,000 feet is easy if you lay the antenna out flat in an elevated position. I put mine on a second floor sun deck and stretched the antenna out along the deck line parallel to the street out front. The signal went over 2,500 feet in the direction of the wire, and another 1,500 feet the opposite direction, too, for a total of 4,000. Of course, the distance at right angles to the wire in the horizontal was around 500 feet and spotty 🙂
Very good for covering a length of a single street, though.
The TH documentation also indicates that greater range can be had by trying literally every possible open frequency. Because the unit auto tunes the wire on power up, you can apparenty sometimes find a ‘sweet spot’ where the environmental factors, ground conductivity, proximity to water, the specific physical size of nearby large-fraction-of-a-wavelength objects, proximity of ferrous metal structural components, the lack of distant skip and a huge basket of other variables hit just right.
I’ve definitely been the beneficiary of these anomlies with other AM low power transmitters so I’m looking forward to doing more testing with my TH.February 24, 2009 at 3:13 am #17108rock95sevenGuest
Total posts : 45366
Im thinking my coverage could be limited to the mobile home park given the metal factor we have going against us. Since my home has metal siding i cant expect all of the signal to escape the house, but i wonder if the TH would be a better transmitter.
I just dont see my amt3000 doing any good outside if i am not able to ground the tx. I thought about putting it on the tongue of the home but i think that would present another problem. Refection off the home and the tongue is so close to where i park my van. We have just enough room to park two cars on either side of the tongue and thats about it.
So at this point i am looking at other options, i have ruled out carrier current, leaky cable, and grounding my sstran outside is not an option.
I think most of you have seen the pictures of my target audience, perhaps the TH could offer just enough coverage for the park despite the metal jungle.
According to the fcc website, ground conductivity in the part of Kentucky is 2.
What do you think?February 24, 2009 at 1:55 pm #17109scwisGuest
Total posts : 45366
I guess my sig says it all, but since you’re about to give it up with your SSTRAN, why not try some experimenting before your make the final decision.
No question, driving a ground rod into a property full of locates (pipes, UGW, etc.) would definitely be a bad idea, however, there are several things I would try before tossing the SSTRAN.
Here are some articles on grounding:
Those pipes, while a real hazard for driving a rod, might be an alternate ground. Using a VOM, check for stray currents on any pipes you can access from your lot and if the pipes are truly “cold,” clip on a ground wire on and see what you get.
Making the same test on the mobile frame, if you find it is isolated from the grid then it really might make a good ground. Same thing with the skin.
You might also try laying a length of wire on the ground in a safe place like around the perimeter of your mobile or around your entire park lot. Using the “cut and press” approach you can even get the wire an inch or two below the surface by cutting the turf and pressing the wire underneath the sod.
AM BCB wavelengths are quite long, so the transmitter is likely indifferent to the vehicles and mobile on your lot.
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