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   Home   Help Search  
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 11 
 on: Today at 04:43:34 PM 
Started by KE4AIF - Last post by WB5ITT
To expand on what Glen posted:
Duplexer: allows simultaneous operation of In band TX and RX on one common antenna and feedline
Diplexer: allows simultaneous operation of two different bands on one feedline  (also called Crossband coupler)
Triplexer: allows simul operation of three different bands etc...

Then you have Combiner and Multicoupler..
Combiner: allows operation of two or MORE transmitters in the same or different bands (usually the same) into a common antenna
Mutlicoupler: allows multiple receivers (may be same or different band but usually within a certain range of a band) to share a common receiver antenna without interaction or loss of performance..
Note the Combiner and Multicoupler requires separate antennas for TX and RX...IN RARE setups, with a wide separation of TX and RX freqs, a wide tuned duplexer can be used to tie it all to one common antenna.....(usually 800MHz systems but this prevents the use of a tower top preamp to improve receiver operation)...

Chris
WB5ITT

 12 
 on: Today at 04:36:10 PM 
Started by WB5ITT - Last post by WB5ITT
Anyone running a FT857D as a rmt base? I am looking for options to control and access all features possible..have a RLC 3 rptr controller which doesnt work 100% and someone advised a RC 210 can work but that means tying the two together...

Any other ideas?

Chris
WB5ITT

 13 
 on: Today at 04:27:31 PM 
Started by KC3NG - Last post by W9IQ
Chris,

Quote
NOTE a rptr that beacon IDs every hour IS illegal unless a control op is monitoring the station during the beacon ID times

You would be hard pressed to substantiate that according to part 97. No control op is needed for a repeater that is under automatic control (ref. 97.205.(d)). The ID is not defined as a beacon. A beacon is defined in part 97 according to the purpose of the transmission. 97.3.(a).9: Beacon. An amateur station transmitting communications for the purposes of observation of propagation and reception or other related experimental activities.

There is no prohibition for identifying more often that the regulations require provided the transmission does not run afoul of other prohibited practices. You will not find anything in part 97 that prohibits a coordinated repeater from identifying more often than required or on a periodic basis. A non-coordinated repeater may have an issue if by doing so, it is causing interference to a coordinated repeater (ref. 97.205.(c)).

With regard to a "Good Morning" or similar preambles, as long as the identification requirements are met, this would simply be considered to be an information bulletin and as such is not prohibited (ref 97.111.(b).6).

Part 97 has nothing to say regarding dropping CTCSS or not so this is not relevant to the discussion.

- Glenn W9IQ

 14 
 on: Today at 04:25:48 PM 
Started by KC1GCG - Last post by KC1GCG
Greetings all,
 I am building a small 20 meter yagi that has loading coils in the elements wound on a 1" wooden dowel.
I believe they are  17 uH .  It calls for 16 Ga enameled wire  but all I can get locally from Rack Shack is 22 Ga. I can online order the 16 of course but am wondering if I can "get away" with the 22 Ga for now as I want to complete this tomorrow? I read one thing that seemed to imply for this application that the diameter of the wire is not an issue but then I found a calculator online for coils and it had an entry for the wire diameter so.....?
My primary question is would the wire gauge/dia have any effect for this application in an antenna?
And thinking out loud on paper using a smaller diameter wire of the same length will result in a different physical length coil .. will this affect this application?
Is electrical length the critical part of this or is inductance or both just to keep it from being easy:) ?
I'm thinking the primary impact will be its power handling capability. The plans I say it will handle full power as designed but since I only run 100W I don't think there is any issue there .....doing some quick ohms law in my head with the 22 Ga. The design and my location to mount it  is such that I can easily rewind them at a later date if I like the antenna and get more power sometime.
Doing some reading from stuff that I have printed from the web on antenna theory etc so working on that too......but my desire to build is exceeding my time to read:)
Thanks in advance and oh yes I currently use a G5RV in case someone wants to lecture me on that being a compromise antenna:)
John Kc1GCG (Kilo Charlie One Golf Causes Grief! )

 15 
 on: Today at 04:23:59 PM 
Started by WA2ISE - Last post by N9CYS
I got my novice in ’71 at the tender age of 14.   Took the general test twice before ’75 – and failed.   I could copy (or so I thought) 15+ wpm but couldn’t get a minute perfect.  The FCC office in Chicago was pretty intimidating.

I had a business meeting downtown in ’86 and walked in on the FCC – cold.  Passed the General!  (I confess that I was active as a SWL.)  Bureaucrat asked me if I wanted to take the Advanced.  I thought what the heck, but the written test was daunting.  I still have respect for the current Advanced hams I work now.  That was the second toughest test I ever took (I’m a PMP.}

I ‘m having a blast working QRP – just picked up a KX2.  Working 800mi today on 5 watts reminds me of the thrill of being a novice.  Hard to believe I’M an OT!

 16 
 on: Today at 04:20:34 PM 
Started by K3TIM - Last post by K7JQ
Aww, Bryan...just messin' with you guys. All in jest.  Cheesy

 17 
 on: Today at 04:19:33 PM 
Started by K6ECS - Last post by WB5ITT
Noise is a subjective matter...if its ON channel, you cannot eliminate it by filters.....I had a 2m rptr at a site that was some what quiet...420 ft up on a smokestack at a power plant....moved the rptr down to the 250 ft level in the plant to gain access to the PBX for autopatch...range went to sh**.......why?? A spectrum analyzer showed the noise floor at the new location was horrible THRU the duplexer (WACOM WP641)....on the bench, the rcvr heard 0.2uV/12DB SINAD....at the site, it took an effective 5uV to open the rcvr....you can check effective sensitivity easily with a Bird Wattmeter and a PAD slug (40db isolation is typical) OR a homemade pad by removing the center pin of a T connector....check the rcvr 1st with the signal generator directly...note the required level...then put the PAD inline with the rcvr and connect the isolated side to the SIG GEN...put a dummy load on the open port of the T (other end to the rcvr) and verify loss...should be about 40 db or so....then connect the antenna....now check the rcvr and see how much MORE signal is needed....add that difference to the original bench level and you get the EFFECTIVE sensitivity of the rcvr on the antenna...some sites are worse than others...

NOW if its off channel noise, you have a crappy rcvr OR a preamp that needs to go (I NEVER run a preamp on a VHF rptr...UHF maybe but depends on the site)....A filter MAY or MAY not help here in this case...but if its ON channel noise, time to find a new site OR find the source of the noise and somehow get it cleaned up (good luck!)

Chris
WB5ITT

 18 
 on: Today at 04:14:44 PM 
Started by M6EES - Last post by G3RZP
About 2 years ago, I was commissioned by Practical Wireless magazine to produce an article on Protective Multiple Earthing. PW never sent me a copy to proof read or a copy of the magazine - rather poor practice - but I think I can send you the original typescript.

You need to email me at g8onatbtinternetdotcom, substituting for 'at' and the 'dot' if you want a copy.
 

 19 
 on: Today at 04:10:28 PM 
Started by KC3NG - Last post by WB5ITT
Yes, among other things I am aware of a repeater that just came on the air and says, "Good moring" whether someone is or had been on the machine with no further ID and I maintained that was illegal.
Renee KC3NG
Did the rptr drop CTCSS on its transmit before a CW ID? or was that a tail msg or ??
Hard to say without more information...NOTE a rptr that beacon IDs every hour IS illegal unless a control op is monitoring the station during the beacon ID times....auto beacons are NOT allowed on all amateur freqs but specific subbands as noted in Part 97..

Chris
WB5ITT

 20 
 on: Today at 04:07:55 PM 
Started by WA9ZWA - Last post by WA9ZWA
I purchased a HG-10 at the Peroria, Il. Hamfest.  It appears that it had been dropped.  The plastic dial bezel (Escutcheon) was broken off and missing.  I wonder if anyone has a "parts" HG-10 lying around?  Or does anyone have an idea how to fabricate a bezel?

Barry
WA9ZWA

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