also switching T/R had some TX spike that activated my SWR protection hence de TX is disabled until reset with power cycle.
The Hi-level mixer XVTR tried also but still blocking on strong local signals
Possible i need to adjust the the level of 116 injection.
This is how the 144/28 transverter.store fits into the K3 with 2nd Rx and KXV3
Also with the original Elecraft 144MHz you will need to fit an extra Antenna connector BNC
I drilled an 20mm pass trough hole to lead the coax through the PA compartment to the 144 BNC This is a delicate job it needs precautions to avoid damage.
I removed the left side panel and used a trapped small multi hole drill with an extension hexa shaft.
those one's are available at eBay and are very good to have.
An automatic 12V 144 band power switch must be added.
A P-channel IRF9540 with some logic switches 12V at 144MHz band
The diagram above shows the 144 bandselect switch it is made on a smal piece of PCB
2 LEDS one = 12V and the 2nd indicates 144MHz band 12V = on
Using the D15 ACC external control signals.
Those signals are convenient also available at the backside 20pole connector J90 of KIO3 shown at top picture.
With the restriction that the D15 ACC connections have a series 220R protection
The soldered wire's bypass the protection 220R
I did insert a protective 220R in the +5V .
I use a 6 pole Dupont detachable connector on the Switch
Overview of connections to 20pole J90 most are also available at the 15p ACC connector
pin20 +5V yellow few mA needed (5V not avail. at D15 ACC)
pin 6 GND white # D15 ACC 5
pin18 DIGOUT0 green # D15 ACC 6
pin14 Band1 blue. # D15 ACC 3 BAND1 OUTpin10 ptt key purple # D15 ACC 10 KEYOUT-LP connected to XVTR key in 3
The 13.6V white-red wire leads to a soldered single header pin at main board right front as described in the K3 144 XVTR manual.
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| Control wire's soldered at the back of 20pole KIO3 J90 same lines of ACC 15pole. Just visible the extra SMD 220R to be soldered over C24 lowering the Q factor of L7 This was needed to stop self oscillation with the K3 top plate closed The XVTR was stable until i closed the top plate (....) The output then sinks from 10 to 9W no big deal. Serge UT5JCW of Transverter.store reacted very quick upon my question about this problem. fb service incredible value for money nice build XVTR As said in previous posts it's performance is real good |
The BAND switch function:
DIO0 is active low for a low power band ie a transverter band and high for HF and 6m.
It is connected to the inverted input Q1 with pull up 10k. The output of Q1 is high when a XVTR low power band is selected.
BAND1 is connected to Q3 with XVTR 144 XVTR address: trn2 BAND1 =+5
For 144MHz Q1 is off hence Q3 is on Q2 is on by BAND1 BCD
Both AND inputs are high the output of Q2 is low making P-channel fet Q4 on
12V is swiched on to the 144 XVTR only when DIO0=low and BAND1=high
Without this auto band switch I had to switch manualy, the top plate had to be off to remove or plug the 12V into the main board.
I believe the newer series K3 have extra XVTR 12V terminals.
Optional
Using a BCD decoder on the 4 BCD BAND signals and DIGIOUT0 = hi-Z , all hf BANDS and 6m are addressed. The lowpower XVTR band have DIGIOUT0 =low the BCD output then follow trn1 - 9
So 9 low power ie XVTR bands are coded with the same BCD lines.
With one internal XVTR only the 144MHz 12V had to be switched
Or 2 bands with the same XVTR i.e. 2 local oscillators can be selected 144-146 and 146-148
I tested an Arduino for band switching but i prefered to keep it simple and reliable as possible.
The RD15HVF1 15W VHF FET is high Efficient 13.6V 1.2A 10W rf at 144 measured
compare this to the old classic BLY89 types 2A 13.6V 10W rf or so
Possible this XVTR does not have the -70 dB image as claimed
But why should I care?
As long as Solar Edge Solar power system can legally pollute 0 300MHz with levels to 9+40db Trash. Why should i care about this?
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