I am trying to figure out a simple tx checkout procedure that doesn't need, say, "connect a 1ghz spectrum analyzer to point x".?
The difficulty with a good procedure to align the the tx is that, it needs to 'see' the RF at fairly low levels of 100 mv or so. This is quite difficult with a simple diode probe. The diode probes work only above 1v levels. One could add an RF amplifier to boost up the levels, but that is just too much complication. does anyone have a better idea of a simple 2-3 component rf detector?
On Sun, Apr 2, 2017 at 7:49 AM, John Backo via Groups.Io <iam74@...> wrote:
Mike. please realize that the hfsigs group aligns the BITX40 for RX (to 40m), but does NOT do any TX alignment.
There is one reference to TX and that is to increase the rig current by 100ma. with the PA connected.
Transmit involves the audio mic amplifier, the PA drive, and the PA output voltage. Most likely the mic audio
is ok, if connected properly. But the IRF510 gate voltage and the PA drive need to be set for proper operation.
This involves adjusting RV1 AND R136. Set the current up 100 ma. with the IRF510 connected. This is done
by adjusting RV1. NOTE WELL that the gate voltage on the IRF510 should not exceed 4v. or so.
Then, with the mic connected, try speaking into it in TX mode. Observe the current draw of the IRF510. It should
increase to about 1 amp or so. If it does not, the first thing top try is an adjustment to R136. Slowly increase R136
(the PA drive) until you see an increase in the current draw on transmit. This is the proper procedure to get into TX mode.
See the Topic "BITX40 Low Output Power" (message 23134 and following) for more information.
Jerry, perhaps a short paper on transmitter adjustment is in order? It should be on the same page as hookup
information.
