What I mean is not theoretical but a practical set up , using a signal generator etc ( I do not have a z meter ) just like when we check coax with a gdo !

How can I determine the impedance of a home made open feeder/ladder line ?

Hi all. A happy new year .

What is the ideal value of an antenna  bleeder resistor ?

What is the ideal wattage, for RF of no more than 100 watts  ?

Does it need be a special very high voltage resistor, or any ordinary will do ?

Thanks Bob
73's
and all the best for 2012 to you and yours

I need to buy 450 ohms ladder line spreaders. I remember some years ago, I came across snap on spreaders, but cannot remember the trade name. Any one can help please ?

Hi all. All the best for the festive season.

If gas filled tubes arrestors happen to be either in parallel or in series in a circuit, what will be the aggregate effect ? Reduced/increased trigger voltage, impedance upset etc etc. A typical example is when you have a tube in the antenna top end and another one in the rx front end !!

Can the two windings of a Guanella 4:1 balun be wound on a single core ?
Or has to be two seperate cores ?

Can the two windings of a Guanella 4:1 balun be wound on a single core ?
Or has to be two seperate cores ?

So sorry folks.
The dimentions should have been in cm, thus 1.1.cm or  0.43inches
the other  piece, similar but 2 cm 0.78inches

Hi all,

Can anyone please help me identify this coax cables:

Inner:   solid copper wire
Outer:  ribbed solid copper, PVC covered
OD:      1.1mm(.043 inches)


Inner:   solid copper wire
Outer:  ribbed solid copper, bare, no PVC cover
OD:      2 mm (.078 inches)

Thanks
Paul

Hi All,

Has anyone played around the RF suppressor Ground System?
.
This system is for elevated ground systems, where the shack is located on a top floor.
Basically, the shack's ground terminal and the ground level ground rod, are connected by RG8 coax, shorted at the ground rod end and open at the shack's end, and bypassed by a capacitor between 0.01 and .1 depending on the lowest frequency in use. Is this system really effective ?

My next door neighbour has a 20 foot, 3 inch diameter stainless steel chimney. Can I use it as a dc ground ? Or connect it to the RF ground ?

Hi All,

Has anyone played around the RF suppressor Ground System?
.
This system is for elevated ground systems, where the shack is located on a top floor.
Basically, the shack's ground terminal and the ground level ground rod, are connected by RG8 coax, shorted at the ground rod end and open at the shack's end, and bypassed by a capacitor between 0.01 and .1 depending on the lowest frequency in use. Is this system really effective ?

My next door neighbour has a 20 foot, 3 inch diameter stainless steel chimney. Can I use it as a dc ground ? Or connect it to the RF ground ?

I remember when we use to build an 807 pa stage with a pi output network, we used to include a choke at the output, just in case the dc blocking capacitor fails.

Thanks.
The shorting relay is the best for lightning. The ideal would be a Ross shorting bar relays, but they are made for very high power and very expensive.

 http://www.surplussales.com/Relays/RossRelays.html

 But I will still have the problem with statics. Once I had an R4 vertical and I was lucky that my TS850 has a GDT gas tube at the input, that saved it all. There were no thunderstorms at the time, just clear blue skies. The problem is that GDT are always quoted as 50 ohms ! That would have solved the problem of statics for the atu. Incidently, GDT do not have to be replaced, once discharged, do they ? I understand that the gas will return to its normal state.

Charles, I have sent you an email  about this subject on    at contesting dot com on the 2nd September.

At present I have a G5RV, but the intension is to experiment with various others, verticals and wire