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谁能做Band Reject Coaxial Stubs [复制链接]

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离线BA4RF
 
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只看楼主 倒序阅读 0楼 发表于: 2009-10-09
http://www.qth.com/topten/apnote2.htm

这个东东我想各个比赛台都需要,有没有人(最好是专营电缆的),能做一批?

top ten devices, inc. logo
application note 2
subject: band reject coaxial stubs

(the following is a reprint of the september/october 1996 ncj article on harmonic suppression using coaxial stubs written by top ten devices' chief engineer, george cutsogeorge, w2vjn.)

band switching stubs for the single-op two-radio station

early last year ken, ab6fo (now k6la) put out a request on the cq contest reflector for help in constructing automatic band switching stubs for his newly designed single op two radio (so2r) station. it looked like a perfect application for the band decoders and 6 way relay boxes available from top ten devices, inc. single band stubs have been in use for many years by contesters to reduce inter-station interference, particularly in multi-op multi-radio stations. in this application, no band switching is required. for a single op, however, rapid band changing is a necessity to be competitive. many of the top operators are using 2 radios which complicates it even further.

figure 1 shows a block diagram of a portion of the so2r station at k6la. one computer controls two radios through com 1 and com 2. each radio has a band switching filter in its rf drive line to an amplifier. these filters reduce the wide band noise produced by the transmitting radio so it is not audible in the receiving radio on another band. they also help prevent overload and damage of the receiving radios front end.

each amplifier has a tvi filter mounted very close to its output. a short run of double-shielded coax, rg-214, then connects to a tee fitting on the stub assembly. the length of this cable is not critical, but it should be well shielded. the tee output goes to the antenna selection relay. this article will not address the antenna switching or the key/mike controls.

the computer lpt ports control two band decoders which supply the relay driver signals to the stub assemblies. simple diode logic is used to select the proper stubs and control signals are passed through to the band switching filters.

there are many ways the stubs could be arranged. these stub assemblies were designed to meet kens requirements. each assembly contains 6 stubs arbitrarily designated as follows:
  a= 1/4 wave shorted 80 meter.
  b= 1/2 wave open 40 meter.
  c= 1/4 wave shorted 40 meter, also acts as 3/4 wave shorted 15 meter.
  f= 1/2 wave open 20 meter, also acts as 1 wave open 10 meter.
  g= 1/4 wave shorted 20 meter.
  j= 1/2 wave open 10 meter.

the switching logic is arranged to utilize these stubs on the following bands:
  160= none
  80= a, nulls 40,20,15,10
  40= b&c, nulls 80&20,10
  20= f&g, nulls 40,15&10
  15= c, nulls 20,10
  10= f&j, nulls 40,15&20

figure 2 shows the wiring of the stub assemblies. the six way relay box has its shortest pc traces on outputs 3 and 4, so they are used for the shortest stubs. the longest stubs are connected to ports 1 and 6, which have the longer pc traces.

figure 3 shows the construction. two steel nema boxes are used to house the stubs. these are available at electrical supply houses. the six way relay box is mounted on the side of the nema enclosure and a uhf double male with a uhf barrel is used to extend the input fitting. all stubs are constructed with rg-213. each stub has an so239 connector on one end and is shorted or open on the other. the ends were coated with glyptol and covered with shrink fit. for the open stubs the shield is cut back 1/4 inch before sealing. all stubs are tie wrapped individually and then tied in place with nylon cord. the diode logic and control connectors are mounted in a small die cast box.

all stubs were cut for low cw operation and still provide some attenuation in the ssb bands. figures 4, 5, 6, 7 and 8 show the attenuation on each band for signals coming from other bands or for transmitter harmonics. an mfj 249 was used as the signal source and a scope or rf voltmeter as the detector. the meter on the mfj did not have the resolution required to cut the stubs close enough. with the rf voltmeter arrangement they could be cut to 10 khz or so.

the stub lengths after trimming were as follows:
  a 45 2
  b 45 0
  c 21 11
  f 21 10
  g 9 10.5
  j 10 2

these numbers should be used as a guideline only for reproducing the stub assembly as there is some variation in velocity of propagation from cable to cable, even from the same lot. its advisable to start with it long and snip down as the null is approached.

after ken had the units installed and operating, he decided more attenuation was required when operating on 40 meters. a second assembly was constructed using two additional stubs. a 1/8 wave cable connects the two assemblies. a dpdt relay normally bypasses the 40 meter assembly except when 40 meters is in use. at the input is a 1/4 wave shorted stub which nulls 20 and 10. the input is connected to the output with a 3/8 wave line and a 1/2 wave open stub nulls 80. performance is shown below.

              band

unit       80     20     10

original   -28 db   -28 db   -24 db

with 40 assy -64 db   -65 db   -41 db

figure 9 shows the 40 meter unit. they were built inside an aluminum chassis with a cover plate. the additional attenuation allows ken to operate his second receiver very close in frequency to the transmitting harmonic.

back to application notes menu

automatic band decoder six way antenna relay a/b station selector
application notes about top ten devices
order products home page send e-mail to top ten devices ham heaven ©2004, top ten devices, inc. all rights reserved
created by scott neader ka9fox of internet solutions, la crosse, wi. 
离线BG4WCE
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1079
只看该作者 1楼 发表于: 2009-10-09
替楼主把图片贴上
figure1

figure2

figure3

figure4

figure5

figure6

figure7

figure8

figure9
离线BA4RF
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4101
只看该作者 2楼 发表于: 2009-10-09
说实话,这个东西不难做,只要有个好一些的扫频仪(频率要准),或者有综测最好。测试出一种类型的电缆应有的长度就行了。
当然要手工好点。

这活最适合做电缆生意的火腿做,嘿嘿。
离线BA7NQ
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10256
只看该作者 3楼 发表于: 2009-10-10
我准备做。你心目中的价钱是??? :d :d :d
离线BD7IN
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1551
只看该作者 4楼 发表于: 2009-10-10
要是你亲自手工做的话,相信lz会给你个公道的价格
离线BA7NQ
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10256
只看该作者 5楼 发表于: 2009-10-10
k1ttt的网站上还有一些:

http://www.k1ttt.net/technote/techref.html#filters

以前大家都是用i.c.e.的,因为提供给ham实用的bpf,目前成品只有i.c.e.和array solutions两种,后者的价格是前者的两到三倍。

一套六波段的独立i.c.e.带通滤波器,要228usd(还没有包括运费)。上面陈老大提供的coax stub,电缆长度加起来不到100米,成本远远低于i.c.e.的带通滤波器,而且,用coax制作,还可以接到功放后面。
离线BA7NQ
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10256
只看该作者 6楼 发表于: 2009-10-10
'
要是你亲自手工做的话,相信lz会给你个公道的价格
'

如果楼主给我分担一下网络分析仪的价格,我愿意送楼主几套。
离线BA4RF
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4101
只看该作者 7楼 发表于: 2009-10-10
'
要是你亲自手工做的话,相信lz会给你个公道的价格
'
是,那是一定的。

nq:要考虑一下能不能采用简便的方法兼顾ssb/cw。看看在ssb电缆上接一段的办法是否可行?另外,你准备用什么电缆做?
离线BA7NQ
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10256
只看该作者 8楼 发表于: 2009-10-10
电缆:给你的用5d-2v或更细,我自己的用rg-213或更粗

ssb的话,根据原文:虽然是按cw来裁剪长度,但也覆盖ssb,不过,具体的要做好之后,实际看看。您提到的接一段上去的方法,完全可行!我觉得最有可能要接的是75/80米,其它波段应该ok。

裁减长度、测量电缆缩短系数是没有问题的,用个mfj-259b之类的天线分析仪就可以做出大概了,以前也做过。我现在比较郁闷的是找不到看波形的仪器。

另外,原top ten的设计方案,使用到了他们的six way antenna relay box,这个价格也不贵...不如...你给我一个relay box,我提供全套coax stub。时间要快,24、25号就比赛了。
离线BA4RF
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4101
只看该作者 9楼 发表于: 2009-10-10
'
电缆:给你的用5d-2v或更细,我自己的用rg-213或更粗
'


'
ssb的话,根据原文:虽然是按cw来裁剪长度,但也覆盖ssb,不过,具体的要做好之后,实际看看。您提到的接一段上去的方法,完全可行!我觉得最有可能要接的是75/80米,其它波段应该ok。
裁减长度、测量电缆缩短系数是没有问题的,用个mfj-259b之类的天线分析仪就可以做出大概了,以前也做过。我现在比较郁闷的是找不到看波形的仪器。
'
我以前做过一根,发现在ssb电缆后面加上一节4cm的转接头就能改变谐振点。所以还是要实践一下。另外,每做一跟就要做相应的标签,注明短路、开路下是什么效果。
如果实在找不到仪器就来南京吧,这里有,就是大家都很懒,不想做...

'
另外,原top ten的设计方案,使用到了他们的six way antenna relay box,这个价格也不贵...不如...你给我一个relay box,我提供全套coax stub。时间要快,24、25号就比赛了。 [表情]
'
你们搞mm还要relay box干什么?
离线BA7NQ
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10256
只看该作者 10楼 发表于: 2009-10-10
'
[表情]
我以前做过一根,发现在ssb电缆后面加上一节4cm的转接头就能改变谐振点。所以还是要实践一下。另外,每做一跟就要做相应的标签,注明短路、开路下是什么效果。
如果实在找不到仪器就来南京吧,这里有,就是大家都很懒,不想做...
你们搞mm还要relay box干什么?
'

我现在想这样,做六个波段的stub,分别接到2x6 sixpak的六个天线座上。这样应该可行吧?但是,要求我六个天线都是单波段的。

但问题是,我现在有些天线时三波段的,有些是两波段的,你说咋办?
离线VR2KW
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3110
只看该作者 11楼 发表于: 2009-10-10
'
我现在想这样,做六个波段的stub,分别接到2x6 sixpak的六个天线座上。这样应该可行吧?但是,要求我六个天线都是单波段的。
但问题是,我现在有些天线时三波段的,有些是两波段的,你说咋办?
'

多加几个塔,把天线都换成单波段的,问题就解决了
离线BA4RF
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4101
只看该作者 12楼 发表于: 2009-10-10
'
我现在想这样,做六个波段的stub,分别接到2x6 sixpak的六个天线座上。这样应该可行吧?但是,要求我六个天线都是单波段的。
但问题是,我现在有些天线时三波段的,有些是两波段的,你说咋办?
'
我想你在分配mm电台的时候一般都会把时间间隔比较远的波段放在一个台上,因此到时候手工切一下就可以了。这样比较简单也可靠。
离线BD7IN
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1551
只看该作者 13楼 发表于: 2009-10-10
'
多加几个塔,把天线都换成单波段的,问题就解决了 [表情]
'
看来b7p(nq)要招商引资了 凡是投资一个塔的就可以终身使用所有天线
离线BD7IS
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9936
只看该作者 14楼 发表于: 2009-10-10
'
如果楼主给我分担一下网络分析仪的价格,我愿意送楼主几套。
'
貌拟广州海印有个陈姓的大佬叫ni的有类似设备。如果唔怕重的话。出来啦
离线BA7JC
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518
只看该作者 15楼 发表于: 2009-10-10
'
看来b7p(nq)要招商引资了 [表情] 凡是投资一个塔的就可以终身使用所有天线
'
b7p不是nq一个的,凡是参与的都应该投资
离线BA7NQ
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10256
只看该作者 16楼 发表于: 2009-10-11
'
我想你在分配mm电台的时候一般都会把时间间隔比较远的波段放在一个台上,因此到时候手工切一下就可以了。这样比较简单也可靠。
'

我现在要应付的是10月底的ssb,搞ms啊!该死得的i.c.e.!邮件、传真、电话,全部不回应!
离线BA7NQ
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10256
只看该作者 17楼 发表于: 2009-10-11
'
貌拟广州海印有个陈姓的大佬叫ni的有类似设备。如果唔怕重的话。出来啦
'

ni那里有!但好像只准欣赏,不许使用!
离线BA7CK
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76373
只看该作者 18楼 发表于: 2009-10-11
'
ni那里有!但好像只准欣赏,不许使用! [表情]
'
呵呵,那就不在他那里使用,直接搬到基地使用,如果有意见大家都去围观他
离线BG4LJW
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12861
只看该作者 19楼 发表于: 2010-10-13
围观老帖~~~~~