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They aren't CMOS unless they are used in pairs for digital logic. :P MOSFET's are less durable than a BJT. They are easily damaged when over voltaged...

That's what I did and my antenna gets the snot knocked out of it off-road...

I would think a boost supply would be much better than a doubler. Doublers don't work very well when loaded...

Well since your reactance went up with an increase in frequency, the X is inductive. However, the phase angle and R are almost perfect at 27.6 MHz => R is about 51 ohms with an angle of less that one degree. I would call it good enough. :) But if you can't, you might be able to...

There is no doubt that grounding is critical, but poor grounding and cable routing can make things just as bad as not having any, if not worse. The nature of lightning (charge) means any conductive object that is high in the air will take a strike before an insulator at the same height. So...

Sometimes..... you can't get a good tune with an antennas current location and it can't be moved for various reasons. So what do you do now? Trimming coax, using an inexpensive antenna tuner, adding reactive components to the antenna base, all do the same thing don't they? :)

I know exactly where you are coming from too. Have fun... :D

:lol: bob85, do you really think the load needs to be that precise? How much error do you think will occur if the load is 5% off? The reason I ask is because you are generating a DAC test signal and recovering/converting an ADC signal when testing, so there is going to be step error and...

http://cgi.ebay.com/ebaymotors/2007-Jeep-Wrangler-JK-CB-Antenna-Mount-UltraMount_W0QQcmdZViewItemQQcategoryZ33639QQihZ003QQitemZ130085599476QQrdZ1 I use a Radio Shack stainless mirror mount style on the tire carrier of my TJ. Though I am staarting to like the new JK the more I see them... :)

bob85, "if after tuning the antenna you cannot get a good match to the feedline does cutting the coax to get a decent match at the transmitter also give a decent match at the antenna" The antenna feedpoint will stay the same which means the antenna VSWR has not changed, but the VSWR in the...

Kure Island... I decommissioned USCG LORAN Station Kure Island back in 1991-92 and made a few MARS phone patches from there... 8)

:) The SWR that is measured with a power meter (or SWR meter) only exists inside the coax, and only when the coax is connected between a source and load (which can be an open, short, resistor, antenna, etc...). If the source, load, and coax are all the same impedance (matched), then the...

It looks like an accident waiting to happen... :shock:

The discussion isn't about perfection, it is about trying to understand and learn... :P

Doc, standing wave ratios greater than 1:1 occur because of an impedance mismatch between the transmitters output and coax, or antenna input and coax, or both. When this condition occurs, the signal sees a transition point discontinuity, which creates a reflection, and increases the SWR. The...

:lol:

freecell, tell me how the forward and reflected power is changing at different points within a length of coax. If this is true, what power is the correct one and at which point? SWR is defined as the ratio of Vmax/Vmin, or Imax/Imin, or Zmax/Zmin, and is typically calculated using power...

Doc, the VSWR measured at the antenna is the same as the VSWR measured at the transmitters output, so the coax will still be part of the tuning process unless the coax is cut to a 1/2 wavelength multiple of the tuning frequency. The coax will always be part of the tuned system if the transmtter...

What does this question have to do with "where" VSWR is measured within a given length of coax and if it changes within a given length of coax? If you read my posts closely, I stated that VSWR measures the same anywhere within a coaxial transmission line that stays the same physical length...

The the VSWR should stay the same since the forward and reflected power stays the same... Energy cannot be created or destroyed, only moved around, so the power isn't varying within the coax unless there are losses...