The Potomac Analog FIM is no longer available, nor are the parts to repair them and calibration service is no longer available. The new meters are expensive digital units. But in broadcast we do not
As I posted earlier field measurement is not an accurate method of determining power. I seriously doubt an administration permit such a technique unless it was very dumbed down and produced very 'saf
In broadcast work the antenna impedance is first determined by calculation (now modeling) then the actual impedance are measured when the station is tuned up. Loading coils are not used at least not
If you can find a used FIM 22 it goes from 200 KHz to 550 KHz. That said I can not see determining EIRP by field measurement. There are just two many variables and a degree of engineering skill not p
The sign up procedure fails. There seems to be a problem with the majordomo address. _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
Ahh but I think the FCC will see things much differently. I base this on the existing 60M regs where an ERP is specified: (i) No station may transmit with an effective radiated power (ERP) exceed- in
I would disagree. The signal measured along the ground is affected by ground losses and is subject to ground conductivity even though the charts show maximum gain along the ground. The signal radiate
That is not what I said. The skywave would only be stronger if field measurements on the ground were used to determine power due to various ground losses, ground conductivity, etc. when an RF ammeter
One has to be careful with 5/8 wavelength verticals. A radiator that is physically 5/8 wavelength is already electrically too tall. That is why a 300 foot BC tower would not work well at low angles o
I think Carl may have his time line backwards. In the 20s and early 30s many stations used various forms of wire antennae including dipoles and various cage designs. During the 30s Dr Brown and colle
Having worked in the business over 54 years with LW MW and SW transmission systems up to 2 megawatts and having built numerous MW arrays to 12 towers I would respectfully suggest a quick check of fun
You really do not need stranded wire. Bare solid wire is typically used for grounds. and while the standard of 120 radials spaced 3 degress is a well known standard for ground systems, it is very rar
There is no single solution for detuning an antenna it depends on electrical length. For verticals a quarter wavelength or less it is common to have a contactor between the network and the radiating
Sensitivity is not always important. Small loops in general receive less noise and the real exercise is balancing the internal noise floor against the actual signal received. In some cases a loss up
Probably part has to do with the fact that your vertical is 1/8 wavelength and rule of thumb is 1/8 wavelength or less do no have a significant influence unless extremely close. _____________________
A while back on another list there was a discussion about a robust amp can not be built in a table top size. I believe this applies to solid state amps as well. The key to building a gutsy solid stat
Static drain chokes and ground rods should be SOP. The chokes drain static build up which usually prevents direct hits. The chokes are available from various broadcast suppliers. ____________________