Ideal SStran tuning procedure

Hi Jason,

The only time I can think of where a test tone would aid antenna tuning is if you are using a radio to monitor the signal strength.

If you follow the SSTRAN tuning instructions, the modulation may affect the meter readings and you may not get the best performance. Apparently, the magic 13 volts with unmodulated carrier was established to give good audio.

I don't know what happens if you deviate from this, but tuning with modulation may affect the readings.

I don't think there is anything to gained by tuning your antenna with a modulated carrier. By the way, 0 dB referenced to what? dB is always relative. Before the experts tell me I am wrong, even dBm is relative....to 1 milliwatt.

Good luck,

Neil

OK 0db, meaning the output from the mixer to the TX, O db on the meter on the mixer.. Thats where my limiter starts killing signal.

As for the test tone I guess my idea around there would be it would be a nice constant signal, no variations in signal, I felt it would make tuning easier.

I was getting a 11.xx when i was tuning but only spent a few munites doing a quick and dirty job.. So i will be doing fine tuning this weekend.. and re running and burring my Audio and Power lines to the TX.

Jason

Through my trials/efforts, one of the most important things is getting the most grounding you can possibly get. I mean getting wire in the ground over 100'+ and as many as you can possibly get..

My first effort was the antenna/xmtr 8' off the ground with chicken wire (2-25' pieces in an "X" pattern) and a ground rod at the base. Tuning per instructions, the 13 volt "target" tuning voltage was easy with a dead carrier but the bandwidth suked! I had peaks over 20 volts with audio and it looked real good but the quality of the sound suffered badly. It just didn't sound right. It sounded more "clean" on the wire antenna that came with the kit. I was not happy at all. The range suffered also but the settings all looked great..

My second attempt was installing it on a platform I have made of wood about 20' in the air. (8'x10' deck on telephone poles) I covered the entire deck with the chicken wire to give it a "close" ground to work with, kinda like the one on the ground but 20' in the air. I had 1 ground rod at the base of the tower connected to the chicken wire and the base of the antenna/xmtr. I couldn't get the peak that I had on the ground. No where close! By this time I was very angry for all of the work I put into moving everything to the tower. But, I kept the faith..

I contacted Phil at SSTran and he advised me to remove the chicken wire and work on the grounding. I had issues with the tuning changing with connecting the audio feed to the xmtr. I could get a better reading without the lines connected to xmtr. That's one reason I chose to use the FM link idea. That fixed that problem. After that I went nuts on making a ground plane..

Starting tuning voltage was about 7 volts.. That's all I could get. At the base of the wooden tower, I pounded in ground rods at all four corners. I put one in the center directly below the platform. I tied all 5 of them togather with 8ga. copper wire. I had some old spools of single color stranded wire of various gauges and started with 2 over 100'long with a 4' ground rod at the end. (connected to the ground loop at the base) Redid the tuning thing and was impressed! Seen 10 volts on a dead carrier but wanted more! I ran 2 more and the voltage increased again! (near 12 volts) I wanted to add more but I got the idea. I needed more ground!!

I don't know if there's any magical "heigth" above ground that could improve the outcome but I do know that the amount of ground wires does make a big difference on the tuning and the bandwidth. The audio quality improved a bunch! Before it sounded kinda "muffled".. The highs just wasn't right and no audio adjustment could improve it. After adding all of the grounding, it sounded great! Cleaned it right up! The range issue is hard for me to report on because I'm surrounded by 60' and higher trees and I'm in no way above them. I do get around 3/4 of a mile (weak) and there are hot spots over a mile. It's a start.. I'll check again after the leaves fall..

I have an area of clear field that I plan to build a ground area per specs. (120 radials-4/10 wavelength long) at a height of somewhere around 20' for the xmtr above ground. I'll be using electric fence wire for the radials. That will be next years project. right now I'm putting in a driveway over 1700' to get to the road. Sounds like fun, huh..

Jason

The SSTRAN antenna instructions on their website say No Audio while tuning. All 3 front transmitter controls turned counter clockwise. It's important to get not much over 13 volts across TP1 and TP2 or your signal will distort. I think building your antenna just as shown on the website is important. Phil B, who owns SSTRAN and designed the transmitter/antenna has certainly gone to a lot of trouble to fine tune the whole product. After connecting your multimeter to testpoints TP1 and TP2 work the coil taps from top to bottom and find your peak. At this point the adjustment on the radiator (copper pipe) should be at the 7" (middle) mark that you make on the top portions as to the instructions for building the SSTRAN antenna. After finding your peak with the coil taps, then work the radiator a half inch at a time up and down looking for your peak. It is important that you back off a couple of feet from the antenna after each adjustment to get a true reading. You'll note, if you watch your meter, as your hand/body approaches the the coil or radiator your meter will change. Jason, Your ground is MOST important. I notice you're using radials. The Antenna Guy who sells the SSTRAN antenna/coil already made had a system of 6 foot radials, some people say 10 foot radials, the same length of the antenna, others say longer. I had no room for radials and put in a series of 4 - 8 foot grounding rods each spaced 30 feet apart and they greatly improved my range. Stick with it and I think you'll find your system lots of fun to work with. Now, if I've given you any incorrect information I trust PhilB, the designer of the transmitter might come on here as he does from time to time to correct me. Jason, everything you need to know is at the SSTRAN.com website under the external antenna construction plans and directions for tuning. If you follow them completely you should have little trouble. One last thing, noticing that your antenna is at ground level, elevating it per instructions on the website may well give you greater coverage. JimB

I have 8 - ten foot radials, I will try tuning with no audio, my antenna is a modification of the magna and the sstran adjustable mast and non adjustable coil.. IF I find that it's not doing it I can tap the coil with a dremmel and a soldering iron...

I have plans to rebuild my coil and mast acording to the sstran model and see if it helps..

I know groundis important.. thus my 10 foot radials.. felt that was a good point to start.. there about 3 inces below the surface.

Any one know if depth makes a better diffrece vs width..

I mean would the dept of the radial make a difrence in the ground... or does the wide-ness of the radials be better... OR both if i dig up the tips of my radials and pound 6 foot rod in and solder it to it will this make the best of both worlds?

Im sure this all depends on the soil you have..

I wont be able to do much with my ground system soon as the frost is comming.

All this trial and error makes this a very time consuming hobby 🙂

My SSTRAN transmitter and antenna results look good after only a couple of tests. The base of my antenna is 14 feet high and I have two eight foot ground rods pounded about a foot away from the mast pipe at 3 and 6 o'clock positions.

One test heard my signal, weak, of course, out to 3 miles. A test later in the afternoon was not nearly as encouraging, with a weak signal at 1/2 mile. It might have been too close to dusk for a good test.

I could get the test meter to show 14.5 volts, so I had to use the trim capacitor to reduce it down to 13 volts. Does a voltage of more than 13 equate to an output in excess of 100 mW? Not that I'd want to operate that way, of course.

I want to test more, but I think it needs to be earlier in the day than what I can manage after work, so further testing will have to wait until the weekend.

Using ground rods instead of radials, is there a difference in how far away the rods are from the mast pipe? Should they be symmetrically placed? Should I water the soil around the rods? What's an ideal number of rods?

Following the construction and tuning instructions to the letter seems to have paid off for me, but I still have a lot more testing to do as well as putting the finishing touches on my station before I can call it complete.

Regards,

Scott

Were all in thi same boat of tuning and testing our setup ad tweeking then from there we decide we weii try a totally diffrent tactic...

MY next tactic will be a TX way up on a say 20 foor mast... and a great grounding system... that wouldbe my ideal situation... wont be till next year however

Jason

Jason, From what you've said it seems your most important move at this point is to construct a loading coil with taps according to the SSTRAN website. You can find there the complete instructions and parts list including two sources for the proper wire. You seem to have an adequate ground system and your copper pipe radiator is now variable. The loading coil does the main antenna tuning, the moveable copper radiator is the fine tuner, it will do little until you do the main resonance peaking with the tapped coil. The copper pipe lengths should be those shown in the SSTRAN plans so as to match the coil. Be sure to mark off the upper portion of your upper copper pipe radiator from the bottom at 3", 7" and 11", and have it set at the 7" mark when you tune your coil. Then go from the 7" mark when adjusting the radiator. By the way on the www.SSTRAN.com website under antenna construction is a link to the Antenna Guy. If you're willing to dip into your pocket, you can buy from him the SSTRAN coil ready made. Also look down the list of topics here on the Forum page and find the one called Important Information about the Magnum Antenna by PhilB. He explains therein why the Magnum design isn't completely satisfactory for his SSTRAN transmitters. Jim B

my plan is to build the sstran antenna, I have a fair ground system in place and it wil stay that way untill next year as frost wil be setting in any day now.. but luckly i can make a new antenna and mount it to the old grounding system. So thats the good part i can work on the antenna in the cold snow coverd months and put it into place.. then in the spring, i can improve the ground system..

Jason