Hello, We are in the process of upgrading the YR7M site from SO capable to M/S. That means, among other, a second workplace equipped with transceiver and linear amplifier. We expect to need bandpass
W3NQN via WX0B: set of 6 filters, $525 plus FM-6 switch, $165 Dunestar model 600, $339 All models are 200W capable. This is a large price variation for essentially the same product, so there must be
Mihail-- ICE and Dunestar use capacitive top-coupling between the two parallel-tuned stages. W3NQN uses a series-tuned circuit between the two parallel-tuned stages. This results in the NQN filter ha
As W0UN pointed out the NQN filters are a bit better at filtering and from the test he describes they might handle more power or mismatch then either the Dunestart or ICE filters. If you are M/M or
I have been asked for a few of the details on the filter testing so here is a brief additional note for those who are interested. Time flies when you are having fun. Didn't realize it has been this m
Hello, Dunestar measurements: the first data column is the attenuation to the lower adjacent band in dB. For 15 and 10m the second column is the attenuation to the second lower adjacent band in dB (t
... ... ... In real-world there is a certain isolation between antennas. I have two towers and my isolation betwwn antennas is not too many dozens of decibels. ICE performance is enough for me. If a
DL2NBU presents complete design of W3NQN type BPF at BCC pages. ICE filters have poor attenuation of higher bands. Only 11 dB in 28/21 MHz set. Dunestar is better as it uses center tap on the coil pr
M/S. transceiver and workplace. I use two Dunestar 600's, which I purchased used, and they have worked well for me for about five years. My antennas are only 6 - 10 feet apart and I run 1500W. You ne
Mihail, Some of the best filters I have seen so far for M/S or M/2 are the Dunestar 600's. These can also be run via band-decoder. If you are planning on going for M/M, you won't want switchable band
... My challenge is what I expected to see someone would challenge my earlier message: The filters can take 200W with good SWR or 100W with poorer SWR on the fundamental pass-frequency. The power ha
I always use coaxial stub filters on the outputs of the amplifiers in addition to the bandpass filters between the radio and the amp. The coaxial stubs can provide an additional 30-40 dB attenuation
I agree in principle. However the 30-40 dB attenuation expected appears somehwhat exaggerated from my personal experience and from what I've read. Perhaps there is a more involved system of stubs tha
Several years ago, I bought a DS-600 BPF and had access to an (also brand new) HP4396B network/spectrum analyzer. The resulting measurements are posted to http://www.k6xx.com/radio/dunestar/ds600.pdf
Certainly this is an issue with solid-state radios hooked directly to an antenna ("low-power" operation), but for guys running high power, does not the out-ofband TX crap get significantly attenuated
At 09:05 AM 6/11/2004, R. Kline wrote: I agree in principle. However the 30-40 dB attenuation expected appears somehwhat exaggerated from my personal experience and from what I've read. Perhaps there
Yes, I understand now. That seems like a great system for attenuating 2nd harmonics. Its equivalent circuit (assuning lossless coax) resembles a pi filter. At the second harmonic, the input and outpu
Please explain stagger tuning. Do you tune the other stub to CW and the other to SSB part of the band, and in between a mid-band quarter wave line to provide at least 25+dB over a broader range of fr
transmit. This is NOT true with many (most?) solid-state transceivers. The best place for a BPF is as close to the antenna as possible! Coax L/4 shorted section is a cheap solution. It might involve