Re: PLJ-8LED Freq Counter Debacle Update
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HI Bill! Would you happen to have the schematic of the J310 buffer circuit?
I've been using a plj6led for quite some time, but loose lock on counter when transmitting on 15/10Meters, so would like to try a j310 buffer solution.
Tried to use a couple of 2n2222's but result was really not that good.
Would be great if you could share!
Thanks, 73's de oz8abr Michael.
On Thu, May 15, 2025 at 7:06?PM Bill Leonard N0CU via <billincolo73= [email protected]> wrote:
This is my third unit (the first 2 failed). I ordered this one from AliExpress. It arrived from China in 8 days and continues to operate properly. It was 1/3 the price Amazon was showing and was a hassle-free purchase. I received excellent updates on status and location of the unit during transit from China. This is the first time I have used AliExpress, and I was impressed.
This unit is about 3 dB more sensitive than the previous two units that I purchased from Amazon and is less sensitive to spurs on the R4-C ¡° INJ¡± line. Freq readings are stable on all bands.
I installed a J310 JFET buffer to drive the counter. Although the insertion loss of this device ranged from 4-5 dB over the freq range of interest (2-34 MHz), there was still at least 6 dB of margin above the threshold of the counter, so I didn¡¯t feel additional gain was necessary.
This unit also had the problem with the color code on the provided cable for the signal input- red is gnd and black is the signal line. The color code for the DC power connector is correct.
Bill N0CU
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Bill N0CU
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