Quote:
Originally Posted by bobsgarage
[SIZE="3"]
I looked at spacing and sure enough if you removed every other reflector you could achieve the five and a half inch spacing of the front sections. I actually only had to drill a few holes for the mounting clamps and another because the director spacing wasn't optimal.
After flipping this rear section around and playing with the reflectors I was able to add the rear section to the front. We will call it the "163 XG":
|
Bob, Interesting modification.
Quote:
|
...Results were good. I think I have reached the point of diminishing returns.
|
Yes true.
Still, every small, or not so small, amount of gain adds up.
Quote:
|
... So I'll do back-to-back scans I tried to keep the test within 10 minutes of each other. Then I'll wait a while and do another back to back scan or even do it the next day. I'll test one and then the other and then the other guy back and forth scales with the same I can say to myself , yeah they are consistent. I always use the same components. Same preamp, same down cable, even the same UVSJ.
|
Don't know how far you are from the stations?
Have noticed that stations that are LOS (in Dallas) are most stable between hours of about noon and mid-afternoon.
For stations that are considered '2-Edge' and 'tropo', they (in KY) are generally weaker in that same time range.
Quote:
|
..There was quite a difference between yesterday and today. Although both days were clear, there may have still been some atmospheric conditions contributing to the strength of the scans I did this morning.
|
Distant signals are usually stronger in mornings.
-----------------------------------
You are discovering the tradeoffs of lengthening Yagis vs stacking. Each has some advantage.
For example:
Ideally, stacking gain could approach 3dB for all the channels the antennas were designed for.
Lengthening a Yagi generally increases gain the most at the highest channels. provides less increase in gain for lower channels.
Contrary to popular opinion, doubling length of a high-gain broadband Yagi does not double gain (3dB) for all channels. For theoretical reasons, doubling length of a normal high-gain Yagi will not double gain for even the high channels.
-----------------------------------
Depending on individual circumstances , there may be good reasons to prefer a long Yagi over a stacked pair, or vice-versa.
You are doing some interesting projects.
.