Topband: PTØS Summary
For those who may not have seen it. 3K Qs on 160. http://pt0s.com/PT0S_Summary.pdf 73 - Steve WB6RSE ___ Stew Perry Topband Distance Challenge coming on December 29th.
Re: Topband: BOG Antenna Measurements
I have been looking for information on BOGs and have not been able to find any info on measured impedance values. Other than they are low, depends on ground, etc. I thought I would relate my recent experience. My own experience with 3 500' unidirectional BOGs over very poor ground is that a 220 Ohm resistor appears to be close to ideal for me. YMMV depending upon the ground and how close to the ground the BOG actually is. Mine mostly ride 3-6" above ground on low plants, twigs, etc. and thru the woods. These were installed to reduce crud pickup from neighbors in the belief that they are not as susceptible as the regular Beverages. Operation has shown them usually more beneficial crud reducers but not as good on real long haul DX. The 73-202 cores are wound transformer style and not unun autotransformer versions; the reason is to minimize common mode using the normal suggested seperation of antenna and feedline grounds I hope others share their observations. Carl KM1H ___ Stew Perry Topband Distance Challenge coming on December 29th.
Topband: Good Conditions Tonight on 160?
FYI, this is an unusually good night on the upper end of the AM broadcast band, with a great signal from Kuwait on 1548. Topband afficianados may want to check out conditions. ___ Stew Perry Topband Distance Challenge coming on December 29th.
Topband: BOG Antenna Measurements
I have been looking for information on BOGs and have not been able to find any info on measured impedance values. Other than they are low, depends on ground, etc. I thought I would relate my recent experience. I had tried a couple Beverages in the past at a salt marsh location and did not have much luck. Ground too good, some say. I doubt that was the major problem. May never know for sure. Last year I tried one at a new location ( 50 miles inland from my salt marsh QTH) and was not impressed. However, I used unknown wire and my old beverage transformer. The unknown wire should have worked anyway. I now suspect my old transformer had design or construction problems! This year at the suggestion of a friend, I simply ran a wire, on the ground, about 220 feet in the woods. The 220 was chosen due to the property line and other grass cutting factors. Since I could not find the old transformer, I wound a new one. The new one was the same design as I had used in the past, but was the same core. I got BOG up, I mean down, in time for the CQWW CW contest. WOW! it was all I used on 160, almost all I used on 80 and I even used it quite a bit on 40. For the ARRL 160 contest it was used almost all the time. I probably spent too much time switching back and forth just to see and hear the difference. I had run it unterminated directly away from Europe. The strength of the signals from Europe was fantastic. No pre amp needed. W5s were strong too,naturally with it un-terminated. This week, I ran a feedline out to the far end (SW end). I also received a package of BN-73-202 cores and wound a 4:1 transformer. I figured that may be in the ballpark. The one I wound in November that worked so well had a Z ratio of 3:1 and on an old FT-140-43 core. The old one (which maybe never worked right was a 9:1 ratio)Last night I worked eight stations from Europe, all very good copy on the BOG. I also noticed that when I switched from the transmit antenna to the BOG, unlike the European stations, 6Y5WJ disappeared. So there is some directivity. More BOGs are planned before the CQ 160 contest! So far I have not had time to play with the termination resistor or experiment with any other transformer impedance ratio. My old MFJ seems to be close on reading SWR but is off on the actual R value. With my BOG terminated with 160 ohms, I am reading an SWR of 1.9 across the 160 band. The MFJ 259B is showing no reactance. That is telling me that the MFJ is seeing either 25 or 100 ohms. I also am using close to a half wavelength of coax to the feed point of the BOG, maybe more. If that is the case the other side of the 4:1 transformer must be seeing 400 ohms or 100 ohms. From what I have read, the 400 is probably too high for a BOG. The 100 ohms seems more likely. My intention is to wind a 2:1 transformer (Z ratio not turns ratio) which, if my guess is right, will transform 100 down to 50 and be a good match for my 50 ohms coax, thus the MFJ would give me a 1:1 indication. Should I dare hope for such results? Merry Christmas to all and Good DXing on Topband. 73, Don N4DJ n...@me.com n4dj.com ___ Stew Perry Topband Distance Challenge coming on December 29th.
Re: Topband: PE coated RG6
Thanks to everyone who replied to my question! I think we're good to go. 73, Mike www.w0btu.com ___ Stew Perry Topband Distance Challenge coming on December 29th.
Topband: Happy birthday
Happy Birthday Dec 24 to old Pal Jack VE1ZZ! Frank VO1HP Joe VO1NA Erik. SM5EDX Sent from an iPad2 ___ Stew Perry Topband Distance Challenge coming on December 29th.
Re: Topband: Subject: Re: Why the DX doesn't always work split? Especially on the low bands
On 12/22/2012 08:18 PM, Steve Ireland wrote: On the 16 December, there was a nice opening into the eastern USA with signals to S6, but the static and general atmospheric noise was about the same level - a common phenomenon. As it is summer in the southern half of the world, it is REALLY noisy! I ended up asking for heaps of repeats mainly because of the noise. Perhaps a comment from the other side of that same opening? I called Steve a few times that morning but stopped because even with a 200 Hz filter and audio peaking it was difficult to hear when he came back to people through the callers. They were spread out some but it only takes a couple who call too long or with questionable/unfortunate timing to make things difficult when the DX is S7 and the callers are 20 to 30 over S9. Steve had a relatively small pile (10 callers at a time?) of reasonably well behaved DXers. For me it was marginally OK working simplex but I very likely might have missed it once or twice had he come back to me. I heard Steve answer a few stations who did not copy him right away due to the other callers (I'm assuming, because there were others still calling and they subsequently seemed to hear him just fine when in the clear). That may have slowed his potential QSO rate somewhat but not drastically. With a few more callers or a couple who are particularly eager it can easily go from that to total chaos. Of course there are times when there isn't enough space on the band for all DX with multiple callers to go split. 73, Paul N1BUG ___ Stew Perry Topband Distance Challenge coming on December 29th.
