Following on,
I have a hiss from headphones attached to output jack fed through the polyphase network board. I am able to alter the volume of this hiss. If I touch input pins of IC3, 4 and pin 5 of IC6 I get an ac hum in phones, getting louder through the chain. If I touch the other pins on ic6, pins 1,2 or 3, I get nothing. Voltage on pin 1 and 7 ic6 are correct.?
LO is progrock at 4x receive frequency.?
It looks like everything from capacitors soldered to opamp inputs and polyphase board is good, IC1 is soldered well with no bridges, T3 removed from board to check windings were in correct place, all good. I'm going to use my U3s to inject signal bypassing the tx/rx switch, any other ideas??
The receiver picks up the data burst from the qlg1 gps loudly. Where would this get in given no signals are seen or heard when put onto an antenna??
Andy.

Glad you got it going without too much trouble.
--
73, Bernie, VE3FWF

Two things,

Check the socket pins for good soldering and insure all the flux has not gotten into the socket.
(rise well with Isopropyl alcohol.)

Allison

Pulled out the micro-controller and reseated it.

That did the trick.

Thank you so much everyone for the help

Much appreciated.

Andy
G0OEY

Try pulling?out the micro-controller and reseat.?

If no joy, recheck all the solder joints and touch up as required.
--
73, Bernie, VE3FWF

Yes I have. Before it would start ok with a couple of on/off cycles.

--

开云体育

Ther's also a speed setting for Slow Hell.

Needs to be about 17.

This speed setting will tend to effect the aspect ratio of the characters,
so you can tweak it along with the FSK settings if required to make your
characters look right.

Although you probably know this already, you'll lose sensitivity on Slow Hell
when it comes to weak signals. Slow Hell loses about 10db or maybe more
compared to FSKCW (QRSS). But it does add a bit of variety on the grabbers ;-)

73 de Andy

You need to use the Slow Hell mode for grabber
work.

Use an Fsk bandwidth setting of about 4 or 5 Hz.

If my memory serves me right and there have
been no fundamental firmware changes, then
the U3 should send out normal Fskcw for Qrss
work at the normal 4 to 5Hz, and then double
up the Slow Hell bandwidth so that it is nice
and readable on a grabber screen.

That should get you started.

73 de Andy

Thanks to all..... I'm using 350C and it seems to be be pretty similar to the 30 watt iron I had before. I appreciate all the input.

73, ?Robert KR4VT

Is anyone successfully using Hellschreiber mode on U3S with firmware v3.12a?

I just tried regular and DX Hellschreiber today for the first time and am getting a splattering mess about 20 Hz wide when the signal is monitored using Argo software. ?I regularly use Hellschreiber with my OpenBeacon transmitters and I know what it should look like.

So either I'm missing something obvious or maybe there’s a U3S firmware bug.

73,

John
AA7US

Justin,

For 2m you may find the phase noise fairly high.? Just listening to it bare
with my?2M system suggests that.

For 222 and higher its not what you want to use the harmonics sound bad!
For 432 the third harmonics sound like FM modulated with white noise.

The problem as you go up is so route the signals you need traces and the
traces are transmission lines and likely low impedance at VHF and up so
your going to source current no matter what.? 1pf loading? at 10mhz is?
not significant, at 144 it multiplied by 144 and is significant.

For a quadrature case crosstalk is not an issue they are the same frequency.
I do not think, subject to testing, you can get a 90 degree quadrature at 144
as the divisors are getting small.

FYI a hybrid at 144mhz will give you plenty of bandwidth easily 1% for
amplitude and phase is rarely an issue for wider.? ( I do IQ)? A hybrid
is easy at 144 and a clean lo is all that's needed (everything has to
be well shielded).? I presume you really don't want to do FM with IQ rx.

The alternate is use a fixed LO (crystal) split into I/Q and up convert both
to whatever.? The up convert can be then anything that decent at HF
and not harmonically related.?and a 5351 one channel might do that
well.? I did that with SI570 but that is a cleaner part.

Basically what is fine at 10M does not fly at 2M.? ?I build for 2m for very
low target NF.? I want to hear signals below -144dbm.? The quality of
the LO is critical as at 2M and up you will hear it!? ?Look at KK7Bs work.??

For easy build a good 10M (one that can tune 28 to 30mhz) IQ RX and
put a well done down converter using a 116mhz LO.? Then get a
11 element beam minimum (more like 15 or more would be better).

Allison

开云体育

Thanks Bill, I appreciate the clarification.

Brian VE7JKZ

Hi Brian, I have my U3S on a 10M beacon frequency. And I use the QRP-Labs PA kit. The shaping is accomplished on the PA kit assembly. So on your U3S if you don't use that particular PA you would not select any shaping options in the U3S menu. And there would be no shaping accomplished as far as the U3S goes. There is an app-note? AN-005 on the website that deals with your intended situation . Best of Luck Bill KN8DMK

Allison,?

in order of importance to me is the following,?

1) drive level, those SBL 1 mixers want +7dBm?
2) frequency I'd like to try reaching 2 meters, 222Mhz would be nice. 432MHz would need additional steps.?
3) I need a quadrature pair, so I will need at the bare minimum a pair functional channels.?

with that said I understand the 51531 performs better as the load impedance presented to it increases, with some digital ICs coming in around 10K ohms I would hope that's high enough to minimize the crosstalk issue. Also thank you for mentioning the VGA driver parts I'll have a look, however I fear they too will be low impedance parts. if so I'm back to op-amps and additional parts.?

-Justin N2TOH?

P.S. as you already stated it's a compromise when your trying to keep the cost down.?

P.P.S. the end goal here is to dust off this KK7B phasing board I've had in my junk collection for the last 25 years...??

Thanks, I will.

I would check the LPF capacitors.