- June 1, 2021 at 5:16 pm #117761
I bought a new Procaster transmitter last month or so. I live in an apartment in a growing area of town. There’s not much around here yet other than schools and another apartment complex across the street.
My apartment is on the top floor, but my balcony is not quite as tall as the others below me, restricting antenna height. I also can’t use a ground rod as is recommended in the instructions. Even with a shorter antenna, I’d still violate the 15.219 restriction. Plus, I’m sure management here would not appreicate if I ran a ground wire three floors to a ground rod in the landscaping.
I was hoping to mount the transmitter on the railing, but the railing is plastic. So I did what my lease outlined and mounted the transmitter on a pole set in a 5 gallon bucket cut in half and full of cement and whatever trash I swept off the floor. There might be some ear plugs in that mix. 🙂
I mounted the transmitter to the pole, then lowered the antenna to the highest I could, tightened up the clamps, tuned it and turned it on. I already ran the wiring for it. The ground is the building’s electrical system. Perhaps, one day, I’ll set the transmitter on the ground and stick a wire in the ground to see if there’s a difference in how well the signal gets out because…
…it doesn’t really get out all that well. Not at first at least. I did a few things to improve range. I switched in the transformer on the studio interface because the distortion was awful and modulation was pretty low. Not much hum. Just way too much distortion. I was able to increase modulation quite a bit. It’s about as loud as I can get it before distortion and I still have some, but not much.
Then I realized what my problem was. The processor I’m using is software-based and the on-board audio chipset isn’t very good nor is it flat across the AF band. It’s very mid-heavy. In other words, no peak control.
As anyone attempted to just bypass the studio interface and go directly to the transmitter at all? When I get time (I work 70+ hours a week), I’m going to use a balanced audio source and do it that way. I do need to find out where the lack of peak control problem originates, however, before I dig in further. It’s certainly a learning experience.June 1, 2021 at 6:14 pm #117764
The Procaster is one of the best! I was using the studio processing but I recently got the Schlockwood AM 200 and using that for processing but using the studio I had to find the balance between the modulation depth and the input signal(the adjustment from the outside of case). The modulation depth also gave it more volume and “punch” to the sound and I used the modulation depth and less of the input signal adjust and used the the source volume and got it to the volume of the other stations with no distortion. The peak control operates all the time if using the studio processing. But it has it’s limits if you push it to hard.
I now have bypassed the studio processing as I am using the external processor but I still go through the studio unprocessed. I asked about what you are wanting to know when I got mine and it could be done but Procaster told me that there is a transformer in the studio that acts like an amplifier to get proper audio level input to the transmitter.
You can get 12V power directly to the transmitter and balanced mono to the audio connections directly but you may need more audio from your processor or audio source to get proper volume levels on air. The output of the Schlockwood is a balanced mono TRS not TS and to try it I’d have to reconfigure the wiring and thought of trying it but easier to just do it as designed.
Even with the peak limiting you will still get distortion with too much modulation depth or audio input but you should get to the volume of the commercial stations distortion free. The peak control is being done in the studio processing unless you bypass it with the switch for external processing. The Schlockwood has 3 band separate frequency compression and would have more reduction on the mid heavy audio you are getting and even it out going to the transmitter. The 3 band compression keeps the bass mid and treble balance even no matter what song plays, like the commercial stations. It also has adjustable peak control.
You should get nice range from 3 floors up! Try no ground, and a wire antenna 104″ long, same as the stock antenna length clipped on the top lug and try different shapes with the wire. Get the needle on the meter as high as you can trying different antenna positions. Doesn’t have to be straight up. You still get an electrical ground through the power supply and other processors/computer and audio cables. A pure copper wire will work better than aluminum with 3 joints.June 5, 2021 at 5:26 pm #117775
Thanks for the advice. It’s nice to see what others are doing with their transmitters, especially the Procaster. I’ve not found a lot of videos of people discussing their setup. I’m working a series of videos of my setup, but as I’ve stated in my first post, I work 70+ hours a week. I don’t have a lot of time to mess around with it. It doesn’t seem it’ll get any better once I start college again. I’m trying to do all that I can before fall classes start.
I never used the internal processor on the studio interface at all other than to see how it worked. I tried a few different combnations with both my software processor (which is pretty complex) and the studio interface at 10:1 compression (basically, a soft limiter).
Since my first post, I’ve done more testing and tracing the audio path. Turns out, the computer’s on-board audio isn’t as bad as I first thought. There’s overshoots, but not as bad as the demodulated audio bears it out to be. The 0.7 dB worth of overshoots is likely due to the computer’s audio output, but nothing like what I experienced.
So it’s back to the drawing board, so to speak. I will have to switch out the isolation transformer to get a better idea of what I’m dealing with in the demodulated audio. I know there’s a difference between what I’m modulating and what I’m receiving. I also got a new reciever, so I’ll be testing with it. I need test equipment eventually so I can do a better job at fine tuning this setup.June 6, 2021 at 3:37 am #117779timinboveyParticipant
Total posts : 745
I have been running my Procaster 24-7 for 8 years as of this month.
I’m in a rural, small town with mine mounted to a wood window frame on my attic at three floors about ground with no ground attached.
I use nothing but the built in Procaster processing. It sounds as good and loud as any commercial AM’s in the area. My coverage is about 2 miles tops, during the day. But again, I’m in a small town with a very low noise floor and my antenna is in the clear.
With the built in processing I have it set for 130% positive modulation, asymmetrical. It’s loud and clear. I found no external units really made much difference over the excellent built in processing.
I should mention for reference, I’ve been in commercial broadcasting for 48 years and have been chief engineer for the group of AM/FM station s I work for for the past 33 years. I require good sound and reliability. Ii don’t mention that to brag, but to give reference that I know what I’m doing. In 8 years the Procaster has needed no work or repairs, and coverage and sound quality have remained constant for 8 years.
I find the simplest audio chain is in fact the best. I found no issues with the Procaster included processing even when compared to my commercial station with a 5 year old Nautel transmitter and new Orban processor. Obviously the commercial station must meet NRSC standards and deal with a wide variety of programming elements that the Part 15 station doesn’t. Doubt the Procaster processing could handle the commercial station, LOL.
TIBJune 6, 2021 at 9:18 am #117780
My set up…Hope it shows good here as size is too big.
Simple is best as Tim mentioned.
June 6, 2021 at 9:20 am #117781June 6, 2021 at 1:28 pm #117784
- This reply was modified 2 weeks, 4 days ago by Mark.
Also on UPS back so when power goes off I am still rockin’
Computer has it’s own back up so not on battery outlets
Have about 4 to 5 hours and usually blackouts aren’t that long.
June 6, 2021 at 2:18 pm #117786
Phil, Here’s my range in the daytime with a GOOD receiver like a GE super or Sangean PR-d15 or other quality receiver or a car with antenna on bumper(newer cars with computer screen and antenna in back window not as good). Best in late afternoon to sunset. This is from indoors as you see in pics. I am also getting some carrier current as my signal is getting into the power lines directly into the houses. Found this out from a couple of listeners.
June 15, 2021 at 2:23 pm #117813
- This reply was modified 2 weeks, 3 days ago by Mark.
Thanks for your replies
timinbovey, I’ve flirted around with commercial operations, but nothing like many of my engineering friends who do RF and electrical engineering for a living. My wheelhouse is audio processing as it is what I’ve spent most of my time on and stream processing is what I’ve done the most of. Processing on AM is new to me, so I’ve spent some time learning how to do it.
Mark, when I’m finished writing up my review of the Procaster on my site (that might take a while since I’m not quite finished), I’ll include some photos here so you can see what I have done so far. I’m actually amazed that I’m getting a mile. It’s pretty noisy here.
Since I’m using the buildings electrical system’s ground, I’ve noticed a huge difference in signal as I cross over the property line. Once I leave it, the signal drops off a lot. I have a GE SupeRadio II and I can hear my signal pretty well, even at night with some skywave action. Once I’m not clobbered with work, I’ll have to walk around more during the day and find out how it does.
I’ll have more as time allows.June 16, 2021 at 12:15 am #117814RichParticipant
Total posts : 196
RE: I’m actually amazed that I’m getting a mile. It’s pretty noisy here. Since I’m using the buildings electrical system’s ground, I’ve noticed a huge difference in signal as I cross over the property line. Once I leave it, the signal drops off a lot.
Below FWIW is a graphic with an analysis of the range/coverage of an unlicensed system meeting FCC §15.219 (not including the effects of the propagation environment such as buildings, power lines etc).
The hardware and setup described there could be considered as near the upper limit of the present “state of the art.”
Attachments:You must be logged in to view attached files.June 18, 2021 at 1:55 am #117830Horatio CaineParticipant
Total posts : 37
I have a Procaster. Don’t bother with the ground lug if you’re that far up in the apartment building.
Where I live, we have bad Thunderstorms. The pitfall of the Procaster and Hamilton Rangemaster, if you want maximum coverage, I found it it needs to go outside. I bought mine new, had to send it back, and it works fine.
As far as bypassing the studio interface, that’s up to you. I’m sure it can be done. I have a BW AM Processor I bought when my Commercial Station was still in operation, and I kept it for the Procaster. Since I’m disabled and now forced into retirement, I haven’t put my Procaster into a 24/7 operation mode because I stream full time. I’m young than everyone one here, in my late 50s, so I’m doing a Mainstream/Active/Alternative Rock Format.
I had my backyard about 10 feet above the ground attacked to a galvanized pole. I’m in a small town. I live about 1.5 mile from the Town Square. My signal made it there! I’m getting 2.5 miles.
I saw what Richard Fry showed you and that is the way it should be done. Problem is, it’s not legal, or so they say. Everyone is here to help.
June 19, 2021 at 1:09 pm #117840
- This reply was modified 5 days, 1 hour ago by Mark. Reason: Suggesting illegal operation
Regarding above post. I had to delete a suggestion of ignoring the FCC suggesting that they don’t have the resources to care about you and not worry about ground leads.
This being a legal part 15 forum we have to keep the discussion legal. I don’t make the rules but as moderator I wouldn’t be doing my job letting that go. And I like to be one of the guys and be as lenient as possible. Discussion outside of part 15-219 does come up but it should not be encouraged to not worry about the FCC.
It was suggested not to bother with the ground lug and that’s good advice as you can get good range as I found with no ground and a 104″ length of wire(the length of the stock antenna). You still get an electrical ground via the power supply and audio cables.
Richard Fry illustrates a legal set up with radials. The transmitter has to be mounted at ground level as per rules for the antenna and ground lead. There is no rule regarding what is underground.
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