VK4 10 GHz Portable

[VK5ZD]

Hi

Let's say Sunday 27th from 11am. I can stay out for as long as necessary.

I'll have my Alinco handheld with me for liaison on 2m/70cm/23cm repeaters. Previous posts suggest 147.0MHz as the most suitable but I can also monitor a second frequency on the sub-band (suggestions?).

I'm planning a drive to the Tamborine area tomorrow (more as a tourist) but I'll have a listen for the 10GHz beacons while I'm there just a assess the various sites.

[VK4ADC]

Iain

Following the tests this morning while you were at Tamborine, I rechecked the 10GHz output power and measured +8dBm directly at the output of the transverter. While that is 15dB below what you said you were transmitting (200mW / +23dBm), it makes me wonder why you didn't copy my beacon / signal better. My S-meter was showing S9 on you after I aligned the azimuth and tilt on the dish so I would expect 2 to 3 S-points down on that (i.e. 15 to 18dB) is still around S5 that you should have copied me at. Is it that my receive side is somewhat better or the fact that I have the receive preamp switched on in my IF transceiver ?? I will probably try to spend a bit more time working on the gear tomorrow and see if I can create an improvement in the transmit power out prior to this Sunday's tests.

By the way, I finally powered up my GPSDO this afternoon and cross-checked that 10MHz TCXO using a Lissajous pattern on the CRO and the pattern was rotating very slowly so the frequency error was quite small. It still doesn't confirm which one of us caused the 400Hz discrepancy noted at 10368 but at least it is close at this end, and I have since done a fine adjustment to make it even closer.

73

[VK4EA]

Suggest 439.000 MHz as the liaison freq, and if nothing heard try the Mt Glorious 2m repeater (147.000/146.400 MHz). I'll be listening to both from Bartley's Lookout, Ascot.

Or, try 0449 877 519. 850MHz will certainly work

[VK5ZD]

Hi Doug

Following the tests this morning while you were at Tamborine, I rechecked the 10GHz output power and measured +8dBm directly at the output of the transverter. While that is 15dB below what you said you were transmitting (200mW / +23dBm), it makes me wonder why you didn't copy my beacon / signal better. My S-meter was showing S9 on you after I aligned the azimuth and tilt on the dish so I would expect 2 to 3 S-points down on that (i.e. 15 to 18dB) is still around S5 that you should have copied me at. Is it that my receive side is somewhat better or the fact that I have the receive preamp switched on in my IF transceiver ??

When transverters are involved comparing S-Meter readings is almost meaningless. Aside from the strength of the received signal, the reading will depend on (a) whether or not the pre-amp is on (the FT-817 doesn't have one) and (b) the RX conversion gain of the transverter. What really matters is the signal to noise ratio, but I haven't found a radio which has that as a metering option
Do you get any S-Meter indication when you're not receiving a signal (i.e. just from the noise out of the transverter)?

We were only 27km apart over what appears to be a good line-of-site path. Under those conditions I would have expected a 9+ signal even with just 6mW. Are there any obstructions at your end?

[VK4ADC]

Iain

With no signal received = S2/3 noise with the preamp on, your signal was S9 so it was something >25dB above my receive threshold (assuming approx 6dB per S-meter displayed). If I can get more output level then we may be in with a chance. It was worth a try yesterday and I proved that the 85cm reflector works with the dual band feed !

I have some local bushes in that direction from where I was set up but we may also have the Birnam Ranges partially obscuring the path. I can see parts of Tamborine range on a clear day but mostly the southern end.

We will see what Sunday brings.....

[VK4GHZ]

I'll be out Sunday 11am, looking forward to a first QSO with my new Kuhne G3 10G system.
Unlikely to have the DEM 2.2W PA installed, so will be running barefoot with a nominal 250mW ish.

Location undecided, but I'll be on looking towards Mt Tamborine.
Will have 2/70 FM and 40m in the car.
iChat+ (23 & Above) on the smartphone.

Iain, any chance you can update your VK5ZD/P VK Logger profile with the lat/lon of your intended location?
This is handy to determine a distance and bearing.

[VK5ZD]

Hi

With no signal received = S2/3 noise with the preamp on, your signal was S9 so it was something >25dB above my receive threshold (assuming approx 6dB per S-meter displayed).

Can't understand why there was such a difference in signals. See what happens on Sunday. I've checked the S-Meter on my FT-817 and it's nowhere near 6db per S point. Up to S 5 or 6 it's about 1db per S point! Above that things start getting more realsitic though never what they should be.

Any chance you can update your VK5ZD/P VK Logger profile with the lat/lon of your intended location?
This is handy to determine a distance and bearing.

Profile updated. I'll be at the lookout at the end of Beacon Road, North Tamborine.

[VK4REX]

What frequency is proposed 10368.1 or .15 etc - so we all know where to look

Rex

[VK5ZD]

Hi

What frequency is proposed 10368.1 or .15 etc - so we all know where to look.

Let's say 10368.150MHz. No GPS locking on my system so I'll be +/-200Hz or so.
Is anyone going to GPS/rubidium locked? If so I'll use that as a reference when tuning. I'm interested to know what my frequency error is.

[VK4REX]

I am GPS frequency disciplined so should be within a few Hz

Rex

[VK4GHZ]

Is anyone going to GPS/rubidium locked?

I'm also GPS locked.
In fact, I think most of us up here are.

[VK4EA]

GPS locked courtesy of a trimble thunderbolt, both transverter and FT817

[VK3KGR]

I have finished my transverter so will be looking for my first 10 GHz contact tomorrow. It runs 10 mW with no GPS lock. I will be at Bartleys lookout at Ascot with Peter. The path to Beacon road looks to be un obstructed so signals should be good.

73 Geoff VK4KJJ

[VK4REX]

Hi
Had a great morning, worked VK5ZD, VK4KJJ, VK4EA and VK4OE on 10Ghz, but didn't manage to hear Adam VK4GHZ.
Also worked Doug VK4OE on 24Ghz and had a partial contact with Peter VK4EA on the same band.
Thanks to everyone who made the effort.

Rex

[VK5ZD]

Hi

Good results all round. I worked all the stations participating on 10GHz
My thanks to all for coming out to play.

VK4REX @ Howells Knob, 133km, 345°
VK4EA @ Bartleys Hill, 55km, 349°
VK4KJJ @ Bartleys Hill, 55km, 349°
VK4GHZ @ Mt Coot-Tha, 52km, 338°
VK4OE @ Mt Gravatt, 42km, 348°

After my inital setup I moved a few metres when I found a spot with a better view of Brisbane CBD which is where I pointed my antenna. Geoff's signal (Vk4KJJ) was much better after he replaced the length of RG-58 being used as an antenna feed line. Still not bad for 10mW.

Despite the 11° variation in azimuth I didn't need to move my antenna. The first station I worked was Rex which, as it turns out, was central to the other stations from my location.

Although not apparent in this picture, I am actually beaming through a gap in the trees!