will this work

[1iwilly]

can I use this to check the frequency of tp-1 on cobra 2000 gtl ??? if not a good inexpensive recommendation thanks

Signal Frequency Counter LED Display Digital Frequency Counter 0.1MHz~65MHz Blue | eBay

PLJ-6LED-A is a cost-effective six-digit LED frequency display module specially designed for forum HAM friends. 1PCS frequency counter. Frequency reference. Display digitsï¼ Six-digit common anode LED display, the highest display six digits.

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[loosecannon]

yep you sure can.

I have used MANY of these for that exact thing.
these are the counters i use when i put one in a madison.

they have a great feature where you can program in your IF freq so they can be used with different radio designs.

However!
they are noisy as all get out and will put a buzz in your receive.
there are ways to abate the noise or at least most of it and i believe Nomad has discussed them here at least a few times.

do a search on the forum for "plj6" and choose to search posts by NomadRadio.
you should find the info you need.

if you can't find it, let me know and i'll go check my notes.
i just don't have them with me right now.
LC

 

[nomadradio]

I have installed literally dozens of them into analog VFOs, and few into base radios behind the clock window.

Just remember you have to put a resistor in line with the input wire. Typical value is 220 ohms. The reason is that the input consists of a blocking capacitor that feeds directly into a pair of back-to-back diodes. This is a legitimate way to protect the counter's input circuit, but it will load down the radio's internal PLL signal if you just connect it directly. Tends to reduce transmit power and receiver sensitivity.

We also adopted the habit of connecting the ground wire on the input socket to a .01uf disc cap, and the other side of the cap to a ground foil near the test point where the hot side taps in. This avoids creating a ground loop between the front corner of the pc board and the rear of the board where power gets tapped in for the counter.

We discovered that the counter's internal voltage regulator is happier with 8 or 9 Volts DC powering it. Connecting the power wire directly to the radio's 13.5 Volt power may overheat the counter's regulator chip. Got in the habit of taking a TO-220 7808 regulator and soldering the tab to the ground foil in the rear next to the pc board's big filter cap. Simply leaning the 7808's input leg over to the cap's hot side will work. Adding a bypass cap from the 8-Volt output pin to ground may or may not always be necessary, but we do it anyway. They say anything from a 0.1uf cap and up will work. We got in the habit of using 10uf. Leaving it off could make the 7808 oscillate. It does have a lot of gain built into it.

Easier solution might be to put a 47 ohm 1 Watt resistor in line with the counter's power lead and hook the resistor to the radio's main 13.5 Volt power. Either method will probably work just fine.

The corners of the pc board where the mounting holes are must be insulated from the chassis metal. The chassis is not a proper ground for the radio's internal signals and creating a ground loop tends to put quirky noises into the receiver audio.

73

 

[loosecannon]

well there ya go Willie!

i'll only add to what Nomad posted that i have had luck reducing the noise further by placing a 470uf cap right across the power leads on the counter board.

also, be careful as the wire colors will be wrong on one side.
you'll see what i mean when you get the counter.
LC

 

[1iwilly]

Thanks, guys for the guidance i just want it, for alignment nothing else
especially my yaesu ft-890

 

[1iwilly]

I got a chance to check at tp1009 according to the service manual and the freq checks good there. don't understand why the digital display shows off