John H. Bryant <bjohnorcas@...>
Gary, Guy and I continue to work on hotrodding out individual E100s in various ways. In conjunction with that effort, I had an informal shootout this afternoon amongst all of my Ultralights that don't rely on exterior wire antennas. I also threw the Eton E10, the big brother of the E100 into the mix. I started out with a totally Barefoot E100 as base receiver. It had been aligned but that is all. It was fairly sensitive on MW, top and bottom and did not overload in the RF cesspool on far suburban Vancouver, BC, where I live.
I was using a homebrew audio switching device that allows me to compare the audio from two receivers, one in each ear, or have the audio from one of the two receivers in both phones. I first compared the stock E100 to an aligned barefoot SRF-39FP. The SRF-39 was a bit more sensitive at both the top and bottom of the band. '39 also seemed to be slightly more selective, though that was harder to discern. Of course, the E100 was ever so much easier to operate, etc. I then compared the SRF-39 to a DT-200VX with an upgraded filter. The SRF-39 held its own in sensitivity, but GUy's new filter in the DT-200VX gave it the nod.
From there, I went to the newer (to me) radios and also used my 1" x 12" Booster Bar with the T615 stock and my DT-200vx. The three newer radios were the barefoot E10, an SRF-39FP with an Amidon .5" x 7.3" ferrite bar and new coils out of 40/44 Litz wire, and an E100 with a similar Amidon bar and new coil, but this time, with the coil able to slide on the bar to "align" the radio on each station for optimum performance.... a new strategy that Gary sort of discovered and I adopted even before he got his built :>)
E10: The E10 is far too large to be an Ultralight, but I was hoping it might be competitive enough with the E1 that I could consider taking it overseas instead of the E1 in future travels... It is about 4 times the size of the E100 but only 1/8th the size of the monster E1. Frankly, on MW, the E10 is a piece of trash as a DX radio.... at least in this RF-heavy environment. Its selectivity was pretty awful, actually very noticeably worse than the E100!!! And it was fairly insensitive, too boot. I was very disappointed. This was a unit which has not been hand aligned and maybe that will improve sensitivity, at least some. It should be amenable to inserting the wonderful narrow filter from the E1 and that may (should?) improve the selectivity quite a bit. I'm glad that I bought the radio (at close-out prices), so that I have one example of each of the Eton Elite original series (E1, E10, E100) but mine sure was awful in today's test.
SRF-39FP: This unit was fabricated by Gary and is a very hot performer with its new Amidon ferrite bar and new larger diameter coils. It was the second most successful set of the afternoon. There was no noticeable overloading, but tuning required safecracker hands and it also placed second in selectivity to the E100. One of the more telling tests was hearing KPOJ-620 in Portland, which puts in a fairly weak daytime signal here that is nearly swamped by the CKBD-600 Flamethrower here in Vancouver and KCIS, Edmonds, WA a 5KW station about 50 miles of mostly seawater to my south. With the most careful of tuning I could hear KPOJ audio in one spot with the hotrodded SRF-39FP.. The level was enough for language recognition, but following the program was impossible.
E100: The E100 with a 7.3" Amidon bar and the coil arranged so that it could slide was noticeably more selective and sensitive than the SRF-39FP. The differences were significant and somewhat unexpected (see the barefoot comparison above.) The sliding arrangement increases the sensitivity throughout the band, so I expected that the peaked-up E100 might be the same or better than the '39 at the upper 2/3 of the band. However, I did not expect the E100 to be better than the '39 down low around 600 kHz. Afterall, the '39 was low band aligned at 600kHz and should be peaked up there. Instead, the E100 was head and shoulders above the '39 in the KPOJ-620 test. The KPOJ program on the 100 was easy to follow... a little scratchy and with a few vestiges of splatter, but ever so much better than on the '39. Even though I don't think that the slider coil had anything to do with that reception, over all, it sure made the little E100 into a DX Animal!
My tests were not nearly as formal as Gary's Official Shoot-outs and the findings may well vary somewhat (tho' my money is literally on the E100... I just bought another this evening, making a total of FIVE E100s here.) I'm really glad that Gary is going to do a Summer Shoot-Out. Enough things have changed since the last one (especially the E100, IMHO) that his services are badly needed before the Fall.
Oh, I forgot to mention the tests with my 12" Booster Bar. I put a Barefoot E100 on the booster bar and it was no where near as sensitive as the Amidon-equipped one discussed above. Also, the T615 was not a success in this RF-rich environment when used with the Booster Bar. It overloaded some and just generally misbehaved. I'm unsure whether my Booster Bar is just a poor one or whether none of them can compete with a new Ferrite bar by Amidon, transplanted right into the receiver circuitry. I've more comparison work to do there, but I doubt that booster bar will be in my line-up in the fall. The E100 with an Amidon bar (or maybe three Amidon bars) darn sure will.
In any case, it was a great way to spend a sunny Sunday afternoon on the deck, with light breezes and temps in the mid-60s.
Have a great week!