E100 Hotrodding Assistance Needed!
John H. Bryant <bjohnorcas@...>
After my success at adding the antenna input port to the Sangean DT-200VX, I started into the E100 last night with the same mod in mind. The back cover came off fine (getting it back on is a bit of a challenge until you learn the trick.) The receiver is a stack of two or three boards that I now know are connected to a black plastic frame/skeleton that is, itself, largely hidden by the large upper-most board. I took the two visible screws outta the board and attempted to remove it from the stack, but it just didn't want to come loose. I lost my nerve at that point and tip-toed my way back outta the radio, got it back together and it made it back to factory condition (whew!)
This morning I did find some interior photos of the E100 from HongKongRadioer and I discovered that the tuning knob pulls off. More importantly, I sort of infer that you take off the front cover of the receiver, too, and then dismember the stack of boards and sub-assemblies from the FRONT side. DOES ANYONE KNOW IF THAT IS CORRECT???
My first exploration indicated that there is little room for even the 2.5mm audio jack near the ferrite bar on the E100. I'm thinking that I'll mount one of those audio jacks that fit on circuit boards on the top edge exterior of the radio case (right above the ferrite bar) and run the solder prongs thru the case to a pick-up coil on the ferrite bar. I hate to do this to such a beautiful and useful portable, but I sure do want to be able to hook this puppy to an external antenna.
Finally, as I was making the dial of my table model National SRF-39, I used an analog signal generator and the E100 as a frequency meter. As I was sweeping the generator to establish center points, etc., I got the distinct impression that the stock E100 had sharper IF filters than the much celebrated SRF-39FP. Has anyone compared them side by side for selectivity.
If anyone has been inside an E100, please speak up........
Sorry, no insights on disassembling the e100, but a few weeks ago I
ran the e100 and the SRF units through an exhaustive, musta been 15-
20 minutes long :-), test to see how they allowed reception of
channels up next to strong locals, and the e100 was the clear winner -
easily the most selective stock ULR out there! My guess is that
they designed it to allow shortwave reception with 5 khz separations,
rather than targetting 9 or 10 khz splits, which is an excellent side
benefit for us!
A couple considerations I see with the e100 are:
1. 910 khz images can be prominent in a strong RF urban area
2. mine is a different model than yours, with a monolithic coil that
covers the entire ferrtite and cannot be slid/tweaked for lower band
performance. Per Gary, my upper band exceeds even the Sony TJ-615
away in sensitivity, (HLAZ-1566 and VOA-1575 beware!), but alas the
lower part of the band (<1000 khz) gets progressively weaker, and the
SRFs easily out-hear the e100 on 540 khz. I believe yours and Gary's
have a movable coil which allows more balanced results.
3. Circuit noise/background white noise: noticeable at low volumes
4. AGC a bit squawky when tuning to strong locals
All in all, I'd say it's one of the better ULR packages, and the only
decent digital set with 1 khz tuning.
73 - Kevin S
Bainbrdige Island, WA
--- In email@example.com, "John H. Bryant"
challenge until you learn the trick.) The receiver is a stack oftwo
or three boards that I now know are connected to a black plasticand
attempted to remove it from the stack, but it just didn't want tofactory
importantly, I sort of infer that you take off the front cover ofthe
receiver, too, and then dismember the stack of boards andCORRECT???
2.5mm audio jack near the ferrite bar on the E100. I'm thinkingthat
I'll mount one of those audio jacks that fit on circuit boards onthe
top edge exterior of the radio case (right above the ferrite bar)and
run the solder prongs thru the case to a pick-up coil on theferrite
bar. I hate to do this to such a beautiful and useful portable, butI
sure do want to be able to hook this puppy to an external antenna.39,
I used an analog signal generator and the E100 as a frequencymeter.
As I was sweeping the generator to establish center points, etc., I
These are interesting findings on selectivity of the E100. I wonder if the E10 is similar? I have an E10 I picked up at Fry's Electronics for a measly $29.99, and I've been impressed with its performance and value.
The E10 has a unique "image avoider" feature. The narrower of the two I.F. filters is actually two filters-- one at 450 kHz I.F., and the other at 455 khz I.F. Depending on which one you choose, it can shift a signal by 10 khz if it is an image, allowing clear reception of the frequency. If it's not an image but a true signal, it stays put.
Puyallup, WA USA