I wanted to receive 2m with the good band panorama of the Flex6500. This offers a different experience seeing what happens on the band without tuning all the time.
Also at HF using split the pan adapter is very useful.
My IC7100 performs very well at 6 4 2 and 70cm but it lacks the panorama view.
I tried RTL dongle and SDR-Console but connecting the RTL dongle behind the preamp without affecting the 144 reception was not as easy as I thought. I got extra noise when connecting the 2nd receiver. Also tried N1MM with pan driver but I could not see the signals I heard it should be the other way around ? possible I did something wrong.
Tried an old DEM 144 but that is a huge box with Xtal oven and relay T/R switching.
12V 0.4A and start 1.5A to heat up
I still owned 2 so called Ukrainian transverters , very small footprint 40x80x20mm nice build low priced. low standby power 30mA/12V (real), SS T/R switching no relay's.
As small as it is it brings 10W rf from a RD15HVF1 high efficiency 12V(real) 1.5A .
But they have some issues: spurious in band and self oscillation when boxed in.
When TX-ing 144.310 USB in our local morning round I was reported at 145.585 clear USB signal. Both versions transverter's the normal and high-level with mixer ADE-12 from UR3LMZ. Suspect is the 58MHz xtal x 2 116MHz l.o. the third harmonic 3x58=174MHz. When at 144.310 174-28.31 = 145.69MHz An inband spurious that is amplified by the PA. That's why I did not use them any more.
Another issue is self oscillating, the 4m version does that too.
Self oscillating started as soon as the transverter was top covered. It worked fine ,but when closing the K3 top cover it starts to oscillate.
This XVTR is perfect fitting in a K3.
Shielding the PA output circuit as in the picture above stopped the self oscillations and still 10W at 12V(real value).
I was advised to apply a resistor over the driver L that stopped self-oscillation but reduces output to 7W.
Used it with an eBay 116MHz Rojon but that signal not clean, a good tcxo would be oké The other XVTR with dual-gate mosfet mixer is stil in my K3 unused because of this 58MHz x-tal. the local mixing frequency must be a clear as possible ,all
impurities are injected into the 144 MHz signal.
This XVTR was in my drawer for several years but now given a second chance by
switching off the onboard 58MHz X-tal oscillator ( oscillator base jumper to ground) and inject direct 114MHz to the ADE-12 mixer withe the Leo Bodnar GPS disciplined signal generator, this can be set between 400Hz to 810 MHz with its USB configure program. The signal is very clean. The XVTR is build in a small box 8x10.5x 2.5 cm Alu also heath-sink it drives 3-4 to the input attenuator of my BLF188xr PA.
No extra cooling needed at that level. This box was left over from an 10-15W wide band PA also using the Mitsubishi RD15HVF power MOSFET
About the used housing, I can not find where to buy this size and type housing.
Simple nice profiled u-shaped top and bottom part, hold together with front and back plates.
I have overdrive protection in my PA Arduino controller for safety.
In the flex and K3 too, it is easy to ad an 144MHz XVTR using 30-32 MHz as i.f.
The reports I got so far are good it is a pleasure to work the bands enjoying the help of panorama view.
Next will be the checking with a spectrum analyser but the spectrum is clear no spurious seen sofar.
whole 144 to 146 the span can be tailored smaller or wider PI7HVN local beacon can be seen at 144.422 quite al lot of signals low in the CW part I have here must be local QRM from PC or other equipment but no faint carriers in the Flex pan view they are real signals I have to find the source of.
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