Radio Adventures @ G4GUO

Had a question answered by Tennamast, they can off...

2012-03-01T12:06:33.546Z

Had a question answered by Tennamast, they can offer a dual winch option on new masts for an extra £50. They did point out that the mast can still slide out with the dual winch arrangement, but I guess that is only when it is lowered beyond horizontal. A simple spring loaded latch would be cheaper and safer, but that is too easy.

They did point out that users should read the warning in the instructions, clearly they don't understand health and safety!

Dave, G4AON

Hi Dave, Yes they are, they do warn you in the ins...

2012-02-23T17:20:13.542Z

Hi Dave,
Yes they are, they do warn you in the instructions but it had been a while since I lowered it and I forgot. I will be putting up a 6 ele LFA yagi for 4M this weekend. I won't be making that mistake again!

- Charles

Several years ago I had a Western Electronics Ulti...

2012-02-23T16:02:33.270Z

Several years ago I had a Western Electronics Ultimast, which is similar to the Tennamast, and that had the same design flaw which meant it came crashing down if you forgot to put the bolt in... I always remembered, but the guy I eventually sold it to bent the upper section by forgetting.

Are the current Tennamasts just the same as yours? It's a serious safety issue if nothing else.

Dave, G4AON

Glad you enjoy PC-HFDL I wrote that when I was in ...

2012-02-20T18:14:15.523Z

Glad you enjoy PC-HFDL I wrote that when I was in an enthusiastic mood. I usually have a dozen or so projects on the go and flit between them. That is why everything takes years to complete!

Surface mount parts have abbreviated part numbers....

2012-02-20T18:11:30.479Z

Surface mount parts have abbreviated part numbers.
U411 says C7472Z and that is all the information I have.

Can you give me full Part Number for HD-pvr u411 o...

2012-02-20T18:03:57.770Z

Can you give me full Part Number for HD-pvr u411 on main board. can't be just "sn74lvc2g74"

I remember the day my homemade G5RV came down. Dar...

2012-02-17T17:08:48.900Z

I remember the day my homemade G5RV came down. Darn near broke my heart so I feel your pain. ;-)

"Glacial pace" or not you are still the guy who wrote a program I use daily. Some days 24hr a day. That being PC-HFDL and I am so happy you did as it's still the best. :-)

Ken

Those parts are probably TI parts. U410 part numbe...

2012-01-06T16:56:06.642Z

Those parts are probably TI parts.
U410 part number is "sn74lvc1g97".
Digikey has for $0.44.
U411 part number is "sn74lvc2g74".
Good luck!

Hello Geoff, Nice to hear from you after so many ...

2011-12-01T14:55:31.049Z

Hello Geoff,

Nice to hear from you after so many years.

Yes finally after all this time I have a
proper mast.

As you have probably read I am now working
hard to try and get some of the locals on
DATV. At least I can put out a digital
signal for people to tune their Freesat
boxes with.

- Charles

Hi Charles, Just come across your Blog following a...

2011-12-01T14:15:13.666Z

Hi Charles, Just come across your Blog following a GoogleAlert on GB3VR ! Glad to see you got permission OK on the mast, have a similar one on the back of mine.

Geoff G8DHE

Gerard, I don't know when people post comments...

2011-09-18T11:42:29.782+01:00

Gerard,
I don't know when people post comments either!
I can't think of anything offhand, you could investigate digital CCTV or gut a cellphone that has a camera and use that to stream video or a WiFi video camera operating on 2.4 GHz, or just use analogue 2.4 Ghz

Hi there, Well, blogspot never sends replies, so ...

2011-09-08T20:32:21.183+01:00

Hi there,

Well, blogspot never sends replies, so I never got any notification that you responded. Sorry for replying back so late.

Sounds like you're just using a standard PC/processor for this. What I'm mostly interested in is the ability to send data (2kB/s and up) and maybe even video if dimensions and weight allow it. Imagine a space-constrained R/C plane of up to 1.5 kg. The usual DVB modulators are just too heavy for this purpose. Do you think there are any designs that can meet these space constraints?

Mmmm, I tried on Fedora-9 and it had a kernel pani...

2011-08-24T11:50:17.091+01:00

Mmmm, I tried on Fedora-9 and it had a kernel panic...

Hello Gerard, I seem to have lost my first reply ...

2011-08-20T17:24:43.421+01:00

Hello Gerard,

I seem to have lost my first reply to you.

Yes I am using the FPGA to generate PAL signals.
No I have not found any FPGA cores for DVB-S/S2 mainly as I have not searched for them.

While DVB-S would be quite simple to do S2 is somewhat more difficult as it requires large lookup tables for the LDPC codes and has a deep interleaver 64000 bits. That would require a lot of extra memory. I did look into doing DVB-T2 on an FPGA but decided against it for those reasons (it neads even more memory).

- Charles

Hello Mark, I am putting about 12volts up the spou...

2011-08-20T16:17:47.119+01:00

Hello Mark,
I am putting about 12volts up the spout. They have a switch mode PSU inside them and anything between about 8v and 16v seems fine. Rob M0DTS has done more on them than I have (mainly as I have not had the time). He is going to post something on his website soon. On transmit I use about 0dbm at 850 MHz. - Charles

Hi charles, I have just aquired one of...

2011-08-16T14:32:54.910+01:00

Hi charles,
I have just aquired one of these units
and wondered if you could tell me what is the supply voltage you are using up the F-socket?
I thought of just attaching a SAT RECIEVER but didnt want to blow the units up.
Ive done a search on the internet and not found any technical info on the airspan website.
So any information you could supply would be greatly appreciated.
Cheers Mark
http://g0nmy.blogspot.com

Hi there, I found this blog after searching the i...

2011-08-16T12:10:22.223+01:00

Hi there,

I found this blog after searching the internet for D-ATV projects. I'm working on a DVB-S/S2 modulator myself for a little hobby project. Contrary to a ground station, this is intended to be used in a mobile platform with limited space and weight constraints, although all the power is there that's needed.

In post "Tuesday, 4 January 2011", you show a picture of an FPGA and DAC. You seem to be using them for text overlays and so on, not for modulation, right?

Have you found any DVB-S fpga modulation cores on your searches around the internet?

I don't know, try Googling something like '...

2011-07-12T20:35:07.784+01:00

I don't know, try Googling something like 'SMD component markings'. I suspect you have irreversibly damaged your unit so you may be wasting your time.

These look like small ICs. But when I google I can...

2011-07-12T09:18:55.143+01:00

These look like small ICs. But when I google I cant seem to find them.

What ICs are these? And where can I get them

Hi, I am sorry to hear about your problem. U410 is...

2011-06-12T19:56:34.663+01:00

Hi, I am sorry to hear about your problem.
U410 is marked C97K
U411 is marked C7472Z

Hope that helps and good luck.

- Charles

Unfortunately I have toasted two chips described a...

2011-06-08T20:59:46.055+01:00

Unfortunately I have toasted two chips described as U410 and U411 (top left corner of the second shot).
Could you tell what are theese chips (it's symbols) or post a hi-res photo?

Description of the similar problem can be found there:
http://therepairblog.blogspot.com/2011/04/hauppauge-hd-pvr-wrong-power-supply.html

I recognise that DDK premap design, same one as I ...

2011-05-20T12:29:29.435+01:00

I recognise that DDK premap design, same one as I use :) http://yfrog.com/gyfl8bj

Gavin, M1BXF.

Yes at the moment it is an 8x8 bit font which is t...

2011-04-24T19:45:54.803+01:00

Yes at the moment it is an 8x8 bit font which is then scaled by the code. The text is overlaid on the background. The biggest problem is the interlacing but I have that working now. There is not enough memory on the device to store a high resolution image on the chip so the text is written in real-time on the background. I have thought of storing the image on an SD card and reading that in real-time.

Be good if you could get a smoother font but I sus...

2011-04-24T19:02:48.480+01:00

Be good if you could get a smoother font but I suspect its all down to coding it!

Hello Josue, I used Puff to design the matching ne...

2011-04-01T20:49:05.582+01:00

Hello Josue,
I used Puff to design the matching networks. I started with the manufacturers application note loaded the values into Puff then scaled everything for the lower frequency, then modified the values until I got the expected gain and match. I then had to modify the actual circuit to reproduce the 'ideal' results predicted by Puff. The gain was measured using a Gigatronics power meter. The input return loss was not as good as I had hoped but it should be good enough.