Tracker Scout

BillC

Active member
Hi Denys, I cobbled up a very quick and rough version of your filter as we talked about, I too did not have exact values, but looking at the res Search ults I am sure that you are on the right track. As mentioned I changed the switching diode feeds to 4.7k The images show the filter, a sweep with no switching voltage, 14 volts on the psu, and the sweep with markers at 3mHZ and 4.5mHZ , The vertical scale is on 10 db divisions, I am sure that your neatly built filter block will work as planned . When Ray sweeps it that will prove it
IMG_4018.JPG
IMG_4016.JPG
IMG_4021.JPG
IMG_4020.JPG
IMG_4018.JPG
 

BillC

Active member
Hi Denys, I listened to the net last night and to my ear the Tracker scout has nice crisp and clear audio, very easy to listen to, good luck.
 

Vk2jkn

New member
Hi denys, I wasn’t quite sure if you were talking about the tracker , now I’ve seen the progress. WOW , looks great mate , I’d be happy with 80m and 40m Denys … more than happy actually! Cheers jim
 

VK3ZYZ

Moderator
Staff member
Here is the latest code that cleans up the display a bit to remove most of the flicker.
Also, now has the encoder is using interrupts.
Finally, holding the encoder button down longer now moves the cursor right.
Short push, left, long push, right.
 

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VK3ZYZ

Moderator
Staff member
It is a while since I've played with the Tracker board.
There are some odd things going on but it turns out only one of the boards is at fault. I'm thinking RF is getting into the Arduino on one board. The main difference between the boards is the USB serial chips are not the same, but that may be a red herring.
The first board runs well, while the second chatters the radio's band relays while talking, and on the 14Mhz range, resets the frequency on transmit.
 

BillC

Active member
Try running the Tracker from a fully charged 12 V battery "of cells" if not already? In the mobile installation it would see about 12.6 allowing for voltage drop due to bolted connections,fuse holder resistance , supply wire resistance etc. with battery terminal voltage on abt 13.8v. Just a few ideas , hope not too boring.
 

VK3ZYZ

Moderator
Staff member
Ah!
I had a code problem after all. I'd changed the band numbers but still had a reference to the old bands in a couple of places.
Here is the newest Version...
This fixes the USB/LSB switching as I had not tried USB.
And the band resetting is ok as per the note above.
The files are "A" as published, and "B" for the second board as the cal factor is different.

The second board may still be unstable, I'll have to test it.

To make the USB/LSB switch work, remove R9 and change R6 to 100R.
Then a switch between the input and 0V CN5 switches, open = USB, closed = LSB.
 

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BillC

Active member
Also might be a problem due to surge impedance as a result of overall power supply source impedance over the instantaneous syllabic input bursts to the TX. Howzat for a bit of fun? If that were the case the b+ line at the TX would be varying at a modified audio rate. Try a scope across the TX b+ terminal while feeding in low frequency audio to the mic. input say 50 HZ . B+ should be flat on scope . Bit of muckin around, just an idea,I might be barkin up the wrong tree. Cheers.
 

VK3ZYZ

Moderator
Staff member
Now that the encoder is interrupt driven, it occasionally jumps when the TX is released.
Some 10nf 1206 surface mount caps to the rescue...
Photo on 19-01-2022 at 7.10 PM.jpg

I think it helps.
 

BillC

Active member
The coils seem to be a bit tricky to work on . If you really have to salvage some you could possibly dissolve the cement on the pot cores with a drop or two of acetone or maybe apply some heat from a heat gun to soften the adhesive . I have had some success in the past with those ideas. If I can help let me know. Good luck..
 

VK3YNV

Administrator
Staff member
If you don't have any luck with the dissassembly, try searching aliexpress or ebay for something like
"Adjustable High-Frequency Ferrite Core Inductor"

Here's 10x for less than $5, lots of others probably find a cheaper one if you search more.

tinyurl.com/3ba9v6rj
 

VK3ZYZ

Moderator
Staff member
Thanks for that.
there is one that would work for the bands 7Mhz up as the inductance needed is around 4 to 5 uH....
6uH_Coils.png


But the low bands are looking for a 23 to 29uH.
 

VK3ZYZ

Moderator
Staff member
My Tracker Scout had a fault in the channel select circuitry so it was extensively modded.
The local/remote mux and 1 of 8 encoder ICs were removed. As was the ribbon lead to the channel translator board.
Here is the top view of the mods to change the selector switch from switching 0V to now feeds 8V to the selected channel.
FrontMod1.JPG
I forgot to take a photo with the resistor/zenner removed fix :)


FrontMod2.JPG
This shows the feeds +8V feeds from the switch.
The updated code is included.
 

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VK3ZYZ

Moderator
Staff member
Just for fun, I thought to try adding a diode probe to the output of the filter board and play with some code that sweeps the filters from 1Mhz to 30Mhz, in 250Khz steps. Then, read the diode probe output with an Arduino analog in. The output is using the Arduino Serial Plotter function, for the first time for me!
The red staircase is the 1Mhz steps and the green trace is the output level.
I'm not really impressed to tell the truth. But, now I have a way to test it so adjustments can be made.

This is the result , sweeping each filter in turn,
BandPassFilters1-4.jpg


Closeup of 1...
BandPassFilter1.jpg


Closeup of 2...
BandPassFilter2.jpg


Then, 3...
BandPassFilter3.jpg


Finally, 4...
BandPassFilter4.jpg



I don't really know if this test setup is valid, but it is a starting point for maybe a better system for a cheap bit of test gear. really, I should use the Nano VNA but I thought it could be fun to use the actual Arduino VFO board as its own test set.
 
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