TopBand: ZJ Beverage Box Comments and Update de K5PC

[Phil Clements]

At 09:18 AM 11/6/97 EST, you wrote:
>
>A competent tech can copy that circuit in 10 minutes and generate a
>schematic. There are only 20 components on the PC board and 12 of them
>are the filter.

The schematic usually lists the parts and what they are, and who makes
them. I am sure ZJ makes no in-house parts and that all are available
over-the-counter locally. I should have made myself more clear; I
did draw a schematic, but have no idea about the parts. There is even
a great debate on the MMIC's...which one to buy.
 

>Very true and the antenna signal levels are much lower than on a long
>Beverage. After all it is sold as a Beverage Box...not a EWE box; at
>least in the literature I have here.

It would have been very difficult to name the box a "EWE" box, as the EWE
had not yet been invented when the ZJ box came out!

>At this QTH I am surrounded with 5KW BC stations in the 3 to 10 mile
>range and most of them are above 1400KHz. The IMD generated in all of the
>ZJ boxes repaired here make 160M useless for weak signal DXing.  Perhaps
>if I were to build a BC filter properly matched to the ZJ input impedence
>it would help.
>The ZJ filter is after the 9:1 xfmr and before the MMIC. The 9:1 xfmr has
>both input and output windings to a common ground and all other grounds (
>filter, DC bypass, etc) are also common on the PC board. This is asking
>for ground loop problems.  As mentioned here previously by many others
>that is a poor way to operate a Beverage.

I have never even seen a beverage...must be nice! No ground loop, IMD,
overload, BCI, or any other negatives here on the EWE/ZJ. 
>
>I have another ZJ box here for repair that I have not even opened the
>shipping box yet. 
>I'll be glad to run some tests....any suggestions?

You beverage users are in another league from us "EWE'ers...all my testing
is complete here, and in my situation, the EWE/ZJ is the best RX antenna
I have ever had.

(((73)))
Phil, K5PC


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