re_nelson said:
...haven't been able to locate a real head-to-head comparison of AC's Y10-7-13 versus Winegard's YA-1713.
I think you are correct.
re_nelson said:
...but an unbiased "shootout" would be interesting.
Agreed.
re_nelson said:
... indicates that, boom length differences aside, the two are virtually interchangeable. Given the apparent design dissimilarities, I would guess that the Y10-7-13 and YA-1713 would perform somewhat differently.
They might perform differently, give or take dB.
You have seen the specs:
For Y10-7-13:
9.4 dB Gain* (for VHF band)
The following gain numbers were provided in private communication with Antennacraft employee:
Code:
Ch. Gain* (dB)
8 8.9
11 10.1
*over half-wave tuned dipole
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For YA1713:
Code:
Ch. Gain** (dB)
7 9.1
9 10
11 10
13 10.3
**over reference dipole
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In favor of the Y10-7-13
Antenna gain and bandwidth (to some degree) are improved with wider element spacing.
In favor of the YA-1713
For use in 75 Ohms systems, the somewhat integrated 1:1 balun is probably less lossy than using a conventional 4:1 balun.
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The main design difference seems to be the driven elements:
Winegard uses a 2-cell log design as driven elements vs. the dual-driven folded dipoles of the Antennacraft.
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Regarding comparing two similar antennas:
From:
http://www.antennacraft.com/Support_.html
"A good rule of thumb is that an antenna of comparable size and configuration supplied by different manufacturers will likely give similar performance."
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If someone could provide dimensions of a Y10-7-13, then a comparison of NEC model simulation results of the Y10-7-13 vs. YA-1713 might provide some insight.
The YA-1713 has been looked at with NEC modeling (HDTVprimer, Holl_ands, & others), but the results are a bit confusing. The published NEC results indicate a substantial gain loss for the YA-1713 at channel 13, that likely does not exist (see Holl_ands work). My analysis using 4NEC2 based on my antennas and my field experience with the YA-1713 supports Holl_ands findings.
I have tested four YA-1713s and several other relatively high gain VHF antennas (but don’t have a Y10-7-13). In modeling YA-1713 & other VHF antennas (namely channel-cut antennas), I have noticed that NEC models consistently yield results that are shifted down a few MHz (as compared to actual field test measurements). This could be a source of modeling frustration that has been found with the YA-1713 (i.e. questions regarding model results showing a loss of gain at channel 13).
It could be that typical NEC2 models, in general, (or maybe only at VHF with typical Yagi implementations) show results shifted down in frequency a bit.
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Interpreting the results of field comparisons involving two antennas that have gains that are within a dB or two of each other can be tricky.
For example: the matching to a preamp, transmission line, or whatever is connected to an antenna can make a difference.
I have measured received power at 200 MHz delivered to a signal strength meter from an antenna as the coax transmission line was trimmed one inch at a time. The magnitude of the received power varied in a sinusoidal manner approaching 2 dB p-p variance as the decreasing line length went through multiples of 1/2 wavelengths. Also, when using the same antenna with a different preamp, the output varied very little with changes in transmission line length. In theory, more variation than 2 DB is possible.
There are many other factors: e.g. height above ground, nearness to other objects can affect a specific antenna in one way and different antenna in a different way.
In general, I think the two antennas (YA-1713 & Y10-7-13) might be close enough in performance that differences will come down to implementation and specific channels. These differences are some things that one would almost have to verify at their particular site.
Having said that, like you, I am interested in comparisons, data, and experiments with these antennas.
