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Post by Druid Hills Radio on Apr 18, 2018 16:15:16 GMT
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Post by Druid Hills Radio on Apr 18, 2018 17:31:47 GMT
While I can certainly tell the difference I would liked to have heard a music sample as well.
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Post by Boomer on Apr 19, 2018 2:16:44 GMT
Bass
It's nice to hear that bass out of the I-AM, though on my speakers it sounds more 'boomy', like it needs a little high boost to flatten the sound out a bit on the radio they were receiving on, to keep the clarity.
Radios are already expecting pre-emphasis, a treble boost that starts at under 1000 hz, and hits 10 db increase at 10,000 hz, like turning a treble control up.
On the Talking House and I-AM, instead of a boost or flat response you're getting a treble cut, on top of the lack of pre-emphasis, so that accounts for the boomy sound.
I have a Talking House 3, and it's thin sounding compared to other stations on the dial. I've tried equalizing, and it works on the highs, but add much more bass and it distorts, on my Talking House.
The Talking House line was designed several decades ago, as I understand, and better technology exists these days. If they could change out the PLL with a DDS chip, that would help with frequency stability and could eliminate the incidental low level FM. Even enclosing the PLL they have now in shielding would do a lot to reduce the FM and distortion caused by it.
I'd like to see a version with a tuning knob instead of the auto tuner. Make it work like the ATU, a high-low band switch, tuner and peak signal meter, that would be better for the new market of Part-15 hobbyists.
I can see why it was auto-tuned, for non-technical users. It's also good for remote operation, if you put the transmitter in a box outside, then you can retune by turning the power off for a few seconds.. Maybe keep the auto-tuner, that's what makes the TH series special.
Boomer
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Post by Druid Hills Radio on Apr 19, 2018 17:34:56 GMT
BassIt's nice to hear that bass out of the I-AM, though on my speakers it sounds more 'boomy', like it needs a little high boost to flatten the sound out a bit on the radio they were receiving on, to keep the clarity. Radios are already expecting pre-emphasis, a treble boost that starts at under 1000 hz, and hits 10 db increase at 10,000 hz, like turning a treble control up. On the Talking House and I-AM, instead of a boost or flat response you're getting a treble cut, on top of the lack of pre-emphasis, so that accounts for the boomy sound. I have a Talking House 3, and it's thin sounding compared to other stations on the dial. I've tried equalizing, and it works on the highs, but add much more bass and it distorts, on my Talking House. The Talking House line was designed several decades ago, as I understand, and better technology exists these days. If they could change out the PLL with a DDS chip, that would help with frequency stability and could eliminate the incidental low level FM. Even enclosing the PLL they have now in shielding would do a lot to reduce the FM and distortion caused by it. I'd like to see a version with a tuning knob instead of the auto tuner. Make it work like the ATU, a high-low band switch, tuner and peak signal meter, that would be better for the new market of Part-15 hobbyists. I can see why it was auto-tuned, for non-technical users. It's also good for remote operation, if you put the transmitter in a box outside, then you can retune by turning the power off for a few seconds.. Maybe keep the auto-tuner, that's what makes the TH series special. Boomer Hi Boomer. I own one of the "enhanced" versions. They did more than just enhancing the audio. They added a netting capacitor to zero the frequency as well a power adjust to make sure that it's precisely 100 mW input power. |
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Post by thelegacy on Apr 19, 2018 18:32:39 GMT
Another great Album Rock standard sounding AM TX but I have a few questions:
I had an engineer friend I’ve met from another forum and I discussed my situation since I’m now forced to AM due to a few things I won’t go into.
First question: Is there really 3 different versions of the iAM transmitter as I’ve noticed the V3 of the demo file. If so it could debunk what I’m about to post that this engineer friend told me and some may not like this:
Although the new transmitter has an adjustable power pot inside his version of the iAM transmitter this engineer friend has reveled to me that although this new iAM transmitter has the Album Rock quality I have been seeking out of a part 15 compliant transmitter at an affordable price to me the one thing that will suffer is RANGE!! He has tested this transmitter with several different antenna’s between a CB whip and a few published designs such as the antenna made for the Sstran along side of a MFJ long wire tuner for 160 meters that does go as low as 1.5 Mhz of 1500 Khz.
In His tests the older talking house 5.0 did better than the iAM transmitter he had which he bought when the iAM was first made. Even when he opened the transmitter and turned the pot all the way up the range sucked wind compared to the unmodified and non tampered with Talking House 5.0. He said I’d have to make my choice between Album Rock quality audio and range.
Does anyone have the iAM V3 and how did this compare to the Talking House 5.0? If V3 has the same range as the Talking House 5.0 I’ll save my donation money and buy this ASAP!! for I can’t stand listening to the absolute crappy audio of the Talking House 5.0 and feel its sack religious to put my listeners through such torture as to impose such crappy audio to them.
I’m getting an ATU either the MFJ my engineer friend suggested or have one built for me. If I get the MFJ tuner and we get our Hobby Broadcasting petition made (thanks to Michelle Bradley) I will be all set when it comes to light.
Has anyone got a mile or close to it with the iAM? Has anyone copared theirs to the older Talking House V5? I can’t understand why when he had the power all the way up it did worse than the Talking House with its legal power? Maybe iAM puts out far less but why?
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Post by mark on Apr 19, 2018 21:34:28 GMT
Thelegacy, I as you know am not on AM but I can come up with a suggestion, How do you know if the automatic antenna tuner in that transmitter adjusts correctly for the frequency and is getting max. power to the antenna wire?
Me if I was getting an AM transmitter I would want one with manual peaking of the antenna trim. That Sean Cuthbert one on Ebay for the same price of the Talking house looks like a better deal as it has a digital frequency display(like the Talking house) and a control and a LED light to indicate when you are at peaked for max. power to antenna. It comes in a ready built version and a stereo version also but most people won't be able to get it. It is supposed to be "meeting the part 15 rules"
Just a suggestion. Take a look and contact him with questions.
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Post by thelegacy on Apr 19, 2018 22:15:51 GMT
The Sean Cuthbert transmitter sounds interesting and probably may work.
As far as the Talking House or I AM goes I will be using an external (Home brew ATU or an MFJ-97 antenna tuning unit) to tune to either a 6 Ft copper antenna or 10 Ft antenna.
I can get an adaptor to go from F connector to PL259 and connect it to the back of the Talking House and run the jumper wire to the MFJ-97. My Workman SWR-3P`s field strength meter can help with tuning if I get the MFJ-97 as it don't have a built in meter.
The engineer told me FORGET the automatic tuner in the Talking House or iAM transmitter due to its inefficient coil that has SEVERE power loss. He says the Talking Sign had a better ATU.
According to the engineer this is the first reason the Talking House does not have the range like a Procaster or others. So all his tests are NOT using the crap ATU with it.
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Post by Boomer on Apr 20, 2018 5:36:55 GMT
Seeing a schematic for the Sean Cuthbert unit, it shows a FET final, with a class-E tuning style. The one I have is a 'demo' schematic where you can't see the parts values, but you can tell what some parts are.
Sean's tuning is a single variable capacitor between an output coil and ground, with LED tuning meter, so you position the antenna, then adjust the tuner for the most LEDs to be lighted. That's similar to the way the Procaster tunes, a capacitor and a peak meter.
The main limitation on that simple system is you only get a section of the band it can be tuned to. The Procaster, for example, tunes between 1350 and 1700, and it's probably similar for Sean's transmitter.
A virtue of the Talking House-I-AM, all models, is the tuner is full band, a wide range tuner that can resonate a ten foot wire from 1700 all the way down to 530. It does it by using two coils, one for the upper end of the broadcast band, and a much bigger one for the low end, and switches the appropriate coil in depending on the frequency you set it to transmit on.
Instead of a variable capacitor, the TH/I-AM varies the inductance of the coil, by using 'permeability tuning', where a ferrite bar, like the kind used in a AM receiver loopstick, is slid in and out of the coils. With permeability tuning, you can get a wide range of continuous inductance change in a small space, and it's a method that was used in analog car radio tuners for decades.
It's really something novel that Radio Systems came up with!
Now which tuning system is lossy, variable capacitor or inductor? Well, they both have losses. The capacitor is across the antenna, and 'steals' some of the power, and the inductor includes ferrite, a lossy material. Which loses more, it would probably depend on the frequency and antenna used. It's more important that you get that peak in resonance for most power output.
The perfect transmitter is probably the one that fits your situation the best, the environment you have, how it's to be mounted, cost, audio qualities, and your abilities as an operator. I think it's more important to base your choice on that than range claims really, all things considered.
Boomer
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Post by thelegacy on Apr 20, 2018 18:27:22 GMT
The Sean transmitter is not a 50 ohm output so I can't use the antenna that is being built for me which is 50 ohm and that is a big issue. Plus the range is no where near a mile or 1.5 miles. This is what I need to reach to get to the Deltaville Market. Taylor's is also just shy of 1 mile.
Has ANYONE bought the NEW iAM since ISS bought all the rights to it? This is where it maybe called the ISS iAM 3.0 and not the iAM 5.0 made by Radio Systems.
Plus GLORY GLORY the HUM WAS GONE in the New iAM which means they ether they changed the power supply or they added a filter capacitor inside the ISS version of the iAM that Radio Systems did not have!! If they changed the Power supply hopefully it has that 3rd prong as this effects range.
So if anyone has bought a new transmitter within a few days you may be able to tell me your range compared to the Talking House 5.0 and is that God awful HUM GONE like I heard on the file?
As a Album Rocker this will make or break the deal so please let me know. Also be specific as to your setup, the Radio used, the distance between it and the transmitter and if you can record some Album Rock with your patch cord connected to the Mp3 player please mention if you used straight audio or EQed and processed audio.
Adding Highs is NOT AN ISSUE but what I heard I love this sound and want the transmitter.
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Post by thelegacy on Apr 20, 2018 18:32:44 GMT
Correction: I still hear some hum on the iAM but not nearly as LOUD!!!!!
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Post by thelegacy on Apr 20, 2018 22:28:49 GMT
Update: on 4/20/2018 @ 3:30 PM According to the New Radio Revolution's call to Bill of Information Station Specialist:
There has been No Changes in the design of the iAM Transmitter from the first version of the iAM till NOW. We asked about the 3.0 version of that file and was told that there has been no further mods.
Range decrease issues with the iAM according to the engineer I talked to:
Since this engineer had issues with his iAM transmitter it maybe a sign of where mods have failed as far as range. Or maybe the newer transmitter has been made more venerable to environmental surroundings such as RFI caused by near by cell towers or maybe other RF emissions. What needs to be known is rather the engineer lives near a Radio station or if he too operates Ham Radio gear (A Repeater) this could make the range suffer. Plus is the newer unit venerable to ground loops or RFI comming into its modified audio circuit. Why the decrease in range when their claim is that the newer unit increases range is what we need to look into.
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Post by Boomer on Apr 21, 2018 1:54:33 GMT
Do you know what's causing your hum, Thelegacy?
It's possible you have a bad power adapter, where the capacitor inside has gone bad. If you got it on the used market, check to see if the adapter is the correct type that's supposed to be used with your I-AM, it could have been shipped with the wrong adapter.
Using a Talking House indoors has been a mixed bag. It's meant to be used indoors, sitting on a piece of furniture, with the recording on the chip being played back as a loop, and it's usually fine that way, and I haven't noticed too much hum in my Talking House. You could try to move the antenna wire around and see if that helps.
You can get more hum if you connect other equipment to it, like a studio or computer that's plugged in, and hum can get in the audio through ground loops and the transmitter's own signal getting into your AC wiring and audio equipment's wiring. At that point you can go with snap on ferrite chokes on the power and audio wires to try to reduce it.
If I were you I'd take the transmitter outside, like to a patio, and test, record to the chip or connect up an mp3 player and see if you still get hum in the audio. Indoors, run the unit by itself just connected to power and no external audio, and try a different outlet indoors. Even with hum heard inside, go outside and listen there, sometimes hum is just heard in a room or the building the transmitter is in.
With any transmitter it's best to run it with the antenna free and in the clear, it will make a big difference.
Boomer
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Post by mark on Apr 21, 2018 4:33:46 GMT
Here's something about humming on AM transmitters,
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