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Ok on the math as that's not the overall issue. Ok on the SPT500 from 1976. Now let's talk today's SPT500. First matching network is physically smaller in overall dimensions and attachment to Gnd plane and driven element is slightly different. Bottom insulator is clocked different. Overall...
Ok took mine down and tried your measurements. Results were very poor. Antenna at 23' without capacitance hat has too
much inductive reactance. Now granted my SPT500 has an enlarged matching system so this maybe a possible reason I couldn't duplicate your findings. Anyway I did further tweaks to...
Normal. If you watch the swing you can compensate by shifting your center frequency to minimize the shift or use an antenna tuner to at least protect the exciter.
You tuned your SPT500 for which band?
Never got it resonant but the feed point resistance was low enough with the given reactance to achieve a 1.3:1 but the bandwidth seem to suffer. Centered about 27.455Mhz is where it was about 1.3:1 VSWR.
New matching network solves this and now your 1.5:1 VSWR bandwidth is over 600khz with the...
Kinda getting off the topic. First S-meter readings are relative and not absolute. Maybe a little subjective depending on who's looking. A true 5/8 GP tuned properly should present about 3Dbd of gain. So the EIRP is effectively double the RF applied. Now granted these cheap CB S-meters are...
Yes still using capacitance hat as it necessary for keeping the feed point resistance fairly consistant. I found anything over 23' on the driven element as measured from top of the bottom insulator could not be tuned for near 0 reactence. Always too inductive as shown by both the MFJ269 and...
i have tried to tune these new Hygain SPT500's for use on 11 meters with marginal results. The existing matching network used by Hygain on these antennas needs modifications to tune properly for 27Mhz. Just look at a picture of the original Super Penetrator and you'll observe a noticeable...
Attempted tuning on 11 meters using MFJ269C. Antenna reactance with existing Beta matching shipped with these new SPT500's is poor. I did manage to get close to 1.3:1 but the bandwidth seemed to narrow. Others on this and other forums have noted the significant difference in the matching network...
I own both a TS Sweet Sixteen with Toshiba transistors and a newer unit with the DEI transistors. Running both at 14 vdc there's about a 150 watt difference in output with the same drive level into a 50 ohm dummy load. DEI's draw less current. Running the collector voltage to 15.5 vdc the...
Yes 15.5vdc. Using a Ranger 6900F 150 to excite the DX1600X. My SWR at the output of the amp is 1.06:1. Amp input tuning is very good. Voltage drop is .07 vdc at 1400 watts output. No issues with the DEI transistors. I know of several folks running 16 vdc on this and the TS SweetSixteen with no...
Hello all just wanted to give a short review of this brand new Texas Star DX1600X. In a word fantastic! Yes it has the DEI 2SC2879's. It is very well made with very good parts and very good soldering. Modification is necessary before it will operate, but it's a very simple modification. Not the...
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