[Elecraft] 2.8 Khz vs 2.7 Khz roof
I am looking for something somewhere that will help me decide between the two. Ken ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] 2.8 Khz vs 2.7 Khz roof
How about this: All the K3's sent to VP6DX had the 8 pole filters. I presume that was for a reason. I On Thu, Apr 3, 2008 at 2:39 PM, Ken [EMAIL PROTECTED] wrote: I am looking for something somewhere that will help me decide between the two. Ken ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] 2.8 Khz vs 2.7 Khz roof
Ken, Examine your operating desires for the correct answer for you. If most of your operation is casual, the 5 pole filters will do just fine - remember that the DSP provides the ultimate selectivity. If you are heavy into serious contesting or DX chasing and other situations where you will be operating in a crowded band with nearby strong signals, then you may see a slight benefit with the 8 pole filters. Eric Swartz has a nice writeup on the Elecraft website that may provide some additional information for your decision making. 73, Don W3FPR Ken wrote: I am looking for something somewhere that will help me decide between the two. Ken ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] 2.8 Khz vs 2.7 Khz roof
-Original Message- All the K3's sent to VP6DX had the 8 pole filters. I presume that was for a reason. - Yes, but the reason may have had as much to do with marketing, wanting to make SURE the rig puts it's best foot forward, as it did with actually needing 8 poles. I think this one is a rather easy choice. If you're not sure, go with the stock 5 pole filter. It's free, after all. Use the rig and see how it does. If you're still wanting more, get the 8 pole filter. Or, get the 8 pole filter right off the bat. Put both in the rig and A/B switch between them. Then report back here as to what difference you heard. - Keith N1AS - - K2 5411.ssb.100 - - K3 TBD - ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] 2.8 Khz vs 2.7 Khz roof
S Sacco wrote: How about this: All the K3's sent to VP6DX had the 8 pole filters. I presume that was for a reason. Yes, the 8 pole ones were sourced from INRAD and were available off the shelf. The 2.7's weren't ready yet! -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] 2.8 Khz vs 2.7 Khz roof
Actually, I believe the reason was AVAILABILITY! When the VP6DX K3's shipped, I don't believe the 2.7kHz filters were available yet! And I don't believe the 500 Hz 5-pole's were available at that time either... 73, Tom N0SS At 14:46 04/03/2008, Darwin, Keith wrote: -Original Message- All the K3's sent to VP6DX had the 8 pole filters. I presume that was for a reason. - Yes, but the reason may have had as much to do with marketing, wanting to make SURE the rig puts it's best foot forward, as it did with actually needing 8 poles. I think this one is a rather easy choice. If you're not sure, go with the stock 5 pole filter. It's free, after all. Use the rig and see how it does. If you're still wanting more, get the 8 pole filter. Or, get the 8 pole filter right off the bat. Put both in the rig and A/B switch between them. Then report back here as to what difference you heard. - Keith N1AS - - K2 5411.ssb.100 - - K3 TBD - ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] 2.8 Khz vs 2.7 Khz roof
K5WK: I am looking for something somewhere that will help me decide between the two. Since you're a previous Orion II owner I assume you know all of its filters are 4-pole. As W2VJN ofInrad and Rob Sherwood have previously written, shape factor has *very little* impact on performance as roofing filters beyond about -30 dB on the skirts. The following dats is from Elecraft: http://www.zerobeat.net/mediawiki/index.php/K3_Roofing_Filters 1. 6 dB bandwidth and 6/60 dB shape factor: Filter BW(-6dB) Shape Factor 27002910*2.9 28002888 1.6 *The 2.7k may have wider BW than the 2.8k. This is Elecraft's measurement and my 2.7k closely agrees with it. 2. IMD performance: Filter20kHz 10kHz 5kHz 2kHz 2.7 kHz, 5 pole 100+ 98 92n/a 2.8 kHz, 8 pole 100+ 100 93n/a (You'll never notice 1-2 dB of IMD performance) Price: 2.7k included, 2.8k $125. If you order a 2.8k in place of the standard 2.7k in your initial order, the incremental cost is $95. If you are seriously interested in better filtering for SSB, I would spend my $125 for a 1.8k (or possibly even the rumored 1.5k) in addition to the basic 2.7k, rather than using it for a 2.8k. 73, Bill W4ZV ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] 2.8 Khz vs 2.7 Khz roof
Ken, I am looking for something somewhere that will help me decide between the two. I went back and forth several times before I finally decided to go with the 8-pole filters. 1) The 2.8 Khz filter is actually a bit tighter than the 2.7 Khz filter. As W4ZV writes: 1. 6 dB bandwidth and 6/60 dB shape factor: Filter BW(-6dB) Shape Factor 27002910*2.9 28002888 1.6 *The 2.7k may have wider BW than the 2.8k. This is Elecraft's measurement and my 2.7k closely agrees with it. 2) If you extend the analysis to the skirts, the 2.8 KHz filter shows some significant bandwidth advantage at -30 dB. Using a simple linear skirt approach I first used for comparing the CW filters we see: 2700 2800 - - 6dB 2910 2888 Hz -60dB 8329 4620 Hz slope50.18 16.03 Hz/dB -10dB 3311 3016 Hz -20dB 4315 3337 Hz -30dB 5319 3657 Hz -40dB 6322 3978 Hz -50dB 7326 4299 Hz While the shape/width of the roofing filter is not critical, the added selectivity can't help but be some benefit when the strong station fires up 2.5 KHz away. 3) Eric indicates that the 8-pole filters are tested to a higher standard than the 5-pole filters. They will have less filter IMD than the 5-pole filters. For me, the little things added up. I decided better safe than sorry was the best course of action ... I ordered the 8 pole filter up front rather than possibly regret not doing so every time I used the radio. However, the second receiver will have the 2.7 KHz filter. 73, ... Joe, W4TV ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
