Monday, August 28, 2017

more 70 MHz (4metre band) info

just some more followup on the WIA band plan submission for a tiny slice of  70-87 MHz segment,  WIA asking for 70.000 to 70.500 MHz,  that 500kHz to play with,  definitely more than adequate in my mind, plenty to experiment with.

Noting what Region1 has for a bandplan, if we could get the same slice here (Region3), then obviously we need to use the same Bandplan as Region1 to be able to work Region1 from Region3 during E's.

70.200 MHz  SSB calling.

70.450 MHz  FM calling ,  using 12.5kHz FM channel spacing.

70. 260 MHz       -  AM calling !!   really ??  that's legacy modes for sure.

70.100 to 70.250     that's 150 kHz for weak signal nodes,   heaps of space.

70.300 to 70.500  FM at 12.5 kHz spacing = 16 channels,    that's plenty of channels !!

I think  70 MHz would be good fun, with ducting, tropo and E's propagation modes.

fingers crossed we get a slice to play with.

Tuesday, August 22, 2017

Modifications for the TYT TH-9800 FM quad-bander mobile transceiver

These TH-9800  quad band FM transceivers  (a clone of the Yaesu FT-8900 transceiver) have an issue of blowing the transmit driver FET.  I have documented a modification to fix this, as it would be a considerable amount of work to replace the drive FET, or even the PA FET for that matter. Easier to do the mod and run at less output power, better than having a dead tx PA. It basically adding a 8v (7808) regulator into the supply circuit for the Driver FET,  which is fed hot from the 13.8v DC input.

Reducing RFI from your vehicle for operating mobile

I have documented the modifications to my 4WD  vehicle that I use for mobile and portable operation. It was only that in past year I have decided to operate HF, whereas in the past I only ever had VHF and UHF equipment, so RFI radiating out and also from within the vehicle was not so much of a problem, but is more so for HF.  My web page includes photos.

VK5KK microwave photos from WIA AGM Hahndorf 2017

these are the photos I took of David VK5KK's microwave equipment display,  held on the Open Day, as part of the WIA AGM weekend, 21st May, 2017,  located at the Hahndorf Oval.

David was operating  all bands from 1.2GHz through to 122GHz ,including the 10GHz EME station.

Thursday, August 10, 2017

Photos from WIA AGM in Hahndorf for VK5ZD's microwave equipment

I have now collected and edited up the photos I took from the WIA AGM held in Hahndorf on 20th May 2017 and from the Open Day held on 21st May 2017,  this particular web page contains the photos of Iain VK5ZD's microwave equipment, I documented this to show what different people doing in terms of microwave band activity and experimentation. All bands 1.2GHz through to 122GHz.
I also preparing the same for David VK5KK's microwave equipment.