power from digilite on 23cm

[on4bhm]

Hi,

Is it normal my top of the qpsk signal on my spectrum is only at -20dBm ?
the mar-6 is installed.
is this within spec's?

73's
on4bhm

[g0uhy]

v5.7 normal mod.jpg (650.12 KiB) Viewed 11465 times

Hi,

the o/p of the DigiLite is very low, even with the MAR6 installed. You will probably have to use another couple of devices to give you a level which is ok for your PA i/p. A number of people are testing different devices with a view to produce a companion driver board, watch this space..hi.
I've attached a pic of the o/p of my DigiLite with MAR6 for comparison.

73

Malc

[M0ATV]

I also noticed the same so dont worry, I could detect mine on the sat rx easily by using a small length of smd type solder in output of sma pwr out socket & sat rx with 44 element wimo antenna approx 25 foot above it, but when I connected the digilite to my antenna ( 44 element Wimo ) it could be detected by Brian G3SMU approx 15 miles away also using a Wimo 44 element point to point, he is approx 800ft asl to my 300 asl so did help !
With my mar-6 only device digilite connected into my M68719 small amp, with this connected to my double device MRF-286S amp, it gives me approx 10w out ( 175w rated full output ) but again, this is due to too low a drive stage, so I also need to find a way to boost up the pwr out of the bare digilite, was looking at the mini-kits wide band amp GALI 84 AMP see this page > http://www.minikits.com.au/kits2.html#gali39

[G0KTD]

I have Built and install a G4DDK SPF 5043 Amplifier after my mar6 and it has improved my signals out no end it has the gain 15.5dB at 1296
I now can RX it anywhere in the house upstairs as well and even through the wall will have to set up in the Garage to see if it can be RX from their.
Now to build a larger pa hopefully to get about 10watts or so.

Keith G0ktd

[M0ATV]

Hi Keith, I've just ordered one of the SPF5043 amp kits from Sam, hoping it should finally get my output up enough now to drive my two main amp to get the power output up to a normal level, glad yours is working fine, I've just ordered another two Digilite boards for 23cm builds, just got to order the components from Farnell now to finish them all off......Tony

[G0KTD]

Hello Tony I think with one in line will raise it to about 20 mW? 10Watts with Mitsubishi pa Brick, you could use two to achieve best output around 50-100mW, That is according to M0DTS.that is if I have read it correct.
Had mine on TX for 4hrs today worked fine.
Thinking to build a Mitsubishi or Mrf 286 one for hear only draw back on the 286 it needs 26 volts to run it a little awkward for portable use.

Keith G0KTD

[M0ATV]

Hi Keith thanks for info, for analogue I use M68719 Mitsubushi driven to 10w out, which drives my 2x MRF 286-S amp to around 170w out, using these two amps driven from barefoot digilite Im getting 10w out at end stage, so the extra boost from the SPF5043 amp should lift it up quite nicely, the only downside to the MRF 286 devices is as you say the DC voltage supply to run them, a bit awkward when running /P unless a generator is handy

[M0DTS]

Portable is not really a problem.. just use two batteries in series for 24v, not quite as much power will come from the amp but quite adequate for /p.
Remember these mrf286 amps will run fine off 12v with lower power output.

Rob
M0DTS

[M0ATV]

Quick update to an old thread, now built 2 of the SPF5043 amps & both run at 10w output via output from M68719 brick amp, so cheap easy method of some extra pwr out from digilite, be very careful though as the boards are very small & thin so can stress fracture so easily, I mounted mine in conduite plastic tubing & drilled two small holes for the SMA sockets worked a treat.

[KenW6HHC]

Hi,

I am just beginning to read up on DigiLite in detail. I am confused on one point...what to expect as RF output power from the DigiLite board?

In the well-written CQTV-235 article, Dave G8AJN explains that the typical RF output from the AD8346 modulator is about -10 dBm and with the MMIC buffer amp...I then expected the output from the DigiLite board that I should plan for would be perhaps 0 dBm (or more).

But, I see on this forum, typical measured RF output levels are running typically -12 dBm or less. Did I misunderstand something?? Or do I put too much trust in obtaining the typical values of RF output?

I hope someone can clear up my confusion. 73...de Ken W6HHC