Hi Tom, It turns out the wire size does not significantly impact the inductance with identical turns anyway, but I believe the LPF kits are 0.1mm which is closest to AWG 28. That should work well in a

#vfo #lpf

Can someone tell me the AWG enameled wire size used on the toroids in the vfo/sysgen low pass filter kit? I've got a couple that are banged up and need to be replaced. Thanks... /Tom

#vfo #lpf

Yes, sometimes details matter. With my Antuino using the SNA function, passing the signal thru the 30m QCX LPF, at ~10mhz the signal was down one dB fro a dead short, at ~20mhz it was 36 dB less but n

#lpf

ohwenzelph, The Antuino may have limitations or your setup has errors. First is inset a known attenuator in the same path and see if 40DB of attenuator gets 40db on the Antuino. If it does keep adding

#lpf

When one gets to the -60db level and lower how the test setup is assembled is a factor along with the cables used. A good example is a engineer in the lab not a hardware type doing tests in the low UH

#lpf

I don't think one should neglect the impact of measurement equipment on the accuracy of results. Test equipment is very important, in some cases. When making any measurement, you have to always spare

#lpf

I cannot get below about 36 dB down at ~20Mhz. Using a antuino to measure aa1of

#lpf

Hello all, I needed a 10MHz LPF for a project so I dug out a 30 meter QRPLabs LPF kit I purchased a while back and quickly put together. Measuring the filter response implies I can't get lower than -6

#lpf

There is an "overlay" category in some of the CQ magazine contests, called "TB-WIRES", or Tri-band-Wires, which means that you can use the equivalent (or worse) of a 3-el. triband beam on 20M and abov

#qsx #lpf

No contest that I know of prohibits radios that could operate at higher power than the contest allows. That would prohibit the use of most of the popular Elecraft QRP radios, which have maximum power

#qsx #lpf

My list of radios is long... However a favorite for SSB on the 80/40/20/15/10 is the Tentec Argonaut 505, 1973 solid state QRP SSB transceiver does a full 5W! If I decide to play different, Ft817, Ten

#qsx #lpf

Alan, I've not seen any rule like that. Not to say you can't go and find a contest with rules banning radios capable of power over some number. If you do I'd like to know of it. It may be a fun contes

#qsx #lpf

The QSX looks like a very versatile unit, I'm anxiously waiting to be able to order one

#qsx #lpf

Allison, Yes, but the question I am asking is whether contests have rules that say that rigs capable of more than the specified power are banned? 73 Alan G4ZFQ

#qsx #lpf

Alan, What do the rules say? Depends on the contest. The rules are usually very clear. ARRL contests its 5W CW and 10W PEP SSB. If its mixed mode CW/SSB/DIGIi ts likely tthat and I'm certain of differ

#qsx #lpf

Martin. Your correct and missing the example. For SSB its 10W PEP. To produce a 10W PEP signal you need an amp that can put 5W into each of two tones. So yes of course you turn it down but if you usin

#qsx #lpf

Hi Martin I am not an expert on contest rules but if you wish, you may configure your QSX as a 5W radio rather than a 10W radio. You can set it up to calibrate itself and limit itself to never any mor

#qsx #lpf

Martin, So pushing a 2.5 watt rated transmitter up to 5 watts is allowed? What do the rules actually say? If it is a homebrew rig who is to know how it has been setup or what voltage PSU is used. 73 A

#qsx #lpf

Hi Hnas & Allison, isn't it necessary to have a rig doing max 5 w to qualify for QRP in a contest? If I remember well it is not accepted to just declare using only 5 W out from a transmitter capable o

#qsx #lpf

Martin, For QRP contests you want 10W PEP (SSB), an amp that only does 5W single tone can't do that. So for a full legal QRP SSB contest power you need a bit more robust amp like this that can do 10W

#qsx #lpf