Hello folks,
Antenna questions from an apartment dweller:
The rendering below represents my physical limits.
1 The vertical lines are the 13' high ridge lines
of 1 story apartment buildings. *<APEX @ 13'>*
2 The astric is the feed line in location.
I live in the NE corner apt. (in the South building)
3 Ladder line is not an option due to:
(electrical conduit/cable/Land Lines/etc. in attic
access area) <just don't think I can maintain a clean
feed run with the doorways and near by metal envolved>
4 @ the west end of the buildings there is the main
Pwr/Cable/LLine feeds to both buildings.
Present config is a closed loop running the ridge lines &
crossing over between the 2 apartment buildings
total of 302'
(don't ask) .. was a 287' 80m loop and added to ..
to get lower in the 160m band wid TR-7 & MN-7)
50 ohm coax fed 4' then 10 turn 6" balun<choke>
then about 38-40' to tuner.
Ground consist of 3.5' rod into West Tex rock
4' leadin to tuner
no tvi xmit problems 120w ssb /cw ......
bad rx problems mainly due to tvi horz osc. from
other residents / sum pwr line qrn as well
*NOW*
Due to the need to fund fUnKle Sam's yearly tributes..
the TR7 & MN-7 are gone. <sigh>
Present rig is Atlas 215 and MFJ-752B (Audio Filter)
Tuner is homebrewed T tuner.
Ant Works ok on 40m & 80m ..< 1.3 or less - to 1 >
can't get it below 6 to 1 on 15m.
note: this is with the present home brew tuner ..
Goals:
1 Buy up coming K2 from Elecraft < http://www.elecraft.com/ >
yes that means QRP or possiably QRO=50w out
2 *SSB & CW* operations on 40/30/18/15/12/10m
3 main bands will b 40/30/18/10m
4 if it works on 80 .. kwel .. if not/no loss > thunderboomers
5 build/reconfigure .. whatever .. tuner as necessary ..
6 160m is THE band of choice but realistically .. I did gud to
wk 1000 mi with 100w .. and it's spring now ..
Questions:
1 What is best length for loop? given the bands/physical limits
for tx efficiency and tuneability
Rem: consider coax feed situation
Note: the addition of 45'to the overall loop
which made <west> s/n leg 20'closer to the pwr end
of the apt. complex .. made rx noise even worse..
most of it seems to b Horz TV osc ..
like if u turn on ur tv in same room with rig ..
changes when the text changes on the wx ch for example
hav disconnected tv/cable from my apt slight improvement
I hav contacted cable & pwr companys they both sa
nothing is wrong with their systems .. duh ..
2 Diversity reception > MFJ-1026 < anyone used this unit?
as they sa u can't wk em if u can't hear em....
3 I hav a cpi of Eznec .. but really don't know how to use it
if u configure an ant & send it I will try to look at it ..
West
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S 96' | | North
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- *
East
Tnx fer the bandwidth an any input u may hav .. direct or thru
the reflectors.
73's & GB
de
KA5OAI
QRP-L 1505
http://www.wcc.net/~peacemkr
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