VK Logger Ham Radio Forum Archive

SMA-SO239 Adaptors???

Seems like a weird combination considering SMAs belong in the microwave world and SO239s definitely do not!

I have only one (HF) radio with an SO239 on it. Even my FT817s use N connectors....

Tim VK5ZT

Hmmm seems like a few Pi owners about. My collection: Pi3B Pi2B Pi zero Pi ZeroW OrangePi Lite All run Raspbian Stretch. The Pi ZeroW does almost permanent duty as part of a weather balloon tracking system using VK5QI's software, a decent SDR dongle and a pre-amp. The Pi2B has recently been built in...

Hi Gavin Your problem looks fairly straightforward. Looking at the extract from the GARC publication, you can see that the voltage on pin 3 is obtained by using the two 1 meg resistors as a voltage divider giving 2.5 volts. If you are getting 4.5 volts on pin 3 maybe the bottom resistor of the divid...

Jayson -50dBm is a HUGE signal! Your guess meter should be full scale You should be able to see signals down below -100dBm when all is tuned and working correctly. I can't easily generate an accurate level at 3400 but I can measure levels (on a spec an) there. As such I know the second harmonic of m...

Hi all Here's a few voltages around the RF/Mixer stage of the board. I also confirmed the connection between the RF and mixer sections (thin black line). preamp-mixer voltages.jpg As for the Tx switching..... The low dropout 5V regulator supplies power to the comparator IC. Note that +5 is on Pin 7,...

Hi Jayson Expect the unexpected....where these boards are concerned! I have marked up your photo with where I think the track goes (from memory, I am at work!) Also, check DC on the big SM resistor. One side will have 5 or 6 volts on it...just to make sure the preamp is powered. I have not had any i...

Hi all Something else to consider.... At my Gippstech presentation I touched briefly on providing a lower frequency IF output for use with an SDR. I have been working towards using a Flex 1500 with the transverters. Yeah, I know....you need to have a PC running all the time but I have PCs in the van...

Hi all And now for something completely different..... I have a panel running with a 2 Metre IF. Its Rx only at present as I did it on my development system which has no Tx filters. With rough testing it seems to have very little response on the image frequency. Rx sensitivity seems comparable with ...

Hi Dave et al Interesting about the water getting to the panel antenna. That is one of the issues with those things. It is too easy for water to get into the antenna in the right circumstances. I have a panel that appears to be 'non directional' so may have the same issue. They should drain if verti...

And another thing.... These boards can be extremely microphonic....they ring like a bell if not rigidly supported. (FM-ing of the pll) I have had acoustic feedback from the radio speaker to the board causing howl-round!! There's a reason there is three screws in immediate proximity to PLL1 when its ...

No worries Scott... Also consider removing the stubs on each of the filters. They are useless for our application and only skew the filter response. See the diagram below for how they are wired. Just a simple coupling loop inside the filter unit. There should be a small bit of the loop poking throug...

Scott

If you are ever going to want to move the IF to 432 or similar, put some pins in those six large holes near the micro
so you can reprogram at some stage. I will be explaining the process at Gippstech.

Cheers
Tim VK5ZT

Ben

There's no comparison between Wyong and FN.

Wyong would not even fill a quarter of one of the halls at FN (There are 4 halls the size of big aircraft hangars.)

And yes...the quality and range of gear at FN has to be seen to be believed!

Cheers

Tim VK5ZT

Hi all Multitasking day in my office..... - Lunch (cup of soup,lower left) - stressing a RasbPi2 running qtsdr radio transceiver alongside fldigi - browsing VKlogger - watching youtube video on engineering disasters (occasionally relevent in my workshop)! - looking at Arduino C code for the 3.5 GHz ...

Hi all I guess one use is to make your own taser... that would seem to be a possible end use for these devices. I notice that you can also buy the 1000kV (a million volts!!) version for a bit more money...hmmmmm You may have a few legal problems carting around a home-made taser! Cheers Tim VK5ZT

400kV!!! I would have thought something that small would disintegrate with 400kV nearby.... Some of these Chinese descriptions pay little heed to getting the units of measure right. I have a battery pack supposedly capable of 50,000 mAH That's 50 amp/hours for something not much bigger than a mobile...

Hmmm..

Why do I feel I have missed something???

As an aside, I am giving a presentation on the 3.4 GHz panels focusing on the firmware at Gippstech...

Cheer

Tim VK5ZT

Hi all I will be in Townsville from Wed 18 (today) until Fri 20 this week and over a similar time span next week, in three weeks and one more time after that TBD. Sitting in Brisvegas airport as I type this... I was wondering if there are any microwavers up here. Only have a small hand held this tri...

Lou

That hotel Iain will be at is in Austria.....that would be some microwave contact

Not sure where I will be, however...

Cheers

Tim VK5ZT

Re. NBN 3.4 GHz licences.... Our club just received a letter from NBN Co concerning our 3.4 GHz beacon which is within their frequency allocation. In effect, its our marching orders!!! We now need to relocate the beacon down to the new beacon section in the bandplan and re-licence accordingly! Cheer...