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[WA1GFZ]

I didn't use the input filter but if it has more than 1 layer of wire on it I would think the q is low.

[VE7 Kilohertz]

I am really beginning (well it's been more than 20 years) to loath computers. I too am having issues with my supposedly hot rod box. I am trying to dub my son's DV videos from the camera to the computer using either Windoze Movie Maker or Adobe Premiere, both do stupid things, like random lock ups, and not recognizing the firewire link. Adobe won't play anything longer than 4:59 minutes then it locks up. Arg!!!

But I digress, I went to the shop today and found a few more things needed for this project. 200 Ohm R for testing the cores, small wire, cores etc.

Have a look at the pic and let me know your thoughts. The white wire is 30 ga teflon insulated silver plated, the black/blue is 30 ga Kynar insulated silver plated, and the enameled is around 28 ga, Tony's is in there for reference, the coax is, I think, RG-314, or 374?? It's 50 ohm silver plated stuff too. I have no idea what the core materials are.....pick a core...any core.

Cheers
Paul

[WA1GFZ]

That front toroid looks good. The pot cores are good for the lowfer bands.

[VE7 Kilohertz]

I filed it away inside another box of unused parts and have no idea where it's at now!

 

Too too funny.

I have about 50 of those types of boxes. Too much crap collected over the years and now I am finally getting to be able to use some of it ...and I can't remember what box I put it in. The bulk of the boxes are labeled but only with the "big ticket" items. The little shxt gets forgotten then when you need those 2 holed ferrite cores you know you have a bag of, ya can't find them. 

Ya, computers, ya can't live with them....but ya can shoot them.

Maybe next new years it will get in the way of the .45 Colt.

Cheers

Paul

[WA1GFZ]

It sucks when you bring something home from a flea just to find that missing box of 100 parts.

[WA1GFZ]

Why two streams of the same data? Where are you getting this information? I would like to read about it.

[WA1GFZ]

A stock internal sound card will work fine with Alberto's ver .99. I used it for a year. Don't be afraid to give it a try. You may still need to reduce the op amp gain if you hang it off an I.F.

[WA1GFZ]

BTW Alberto's .99 runs fine on my 1 gig Dell with 500 meg of ram.

[Steve - WB3HUZ]

You just realized this? I posted the message below in this very thread weeks ago. Must be hell getting old.   ; - )

http://amfone.net/Amforum/index.php?topic=12813.msg96793#msg96793

It seems that SDR I&Q are now really 'old technology' and that amateurs are just starting. I had wondered how the newest cell site gear had shrunk so drastically, now I realize it was the use of SDR. These silly little cell phones we've been using for years now are SDR based.

[Steve - WB3HUZ]

Yea, someone told me to have an open mind. I tried it and my brain fell out.


Most people didn't notice.

[WA1GFZ]

Huz,
I friend in the know told me the cell phones use SDR and also DDCs ( digital down converters.) The DDCs in cell phones have limited dynamic range. A cell site every couple miles makes this usable. The HPSDR guys jumped on the DDC idea so I reported the limited performance. Phil Covington found out in his first quick silver design. The new Quick Silver has that function stuffed in a FPGA to get better performqnce.
The present configuration is to sample at 125 mhz and DDC to a lower frequency that the DSP can handle. I think he also has a step attenuator ahead of the a/d to slide the dynamic range up and down. I still think this configuration like all SDRs need a good preselector ahead of them. Why do I think this? You look at an AM signal on the flex display near the noise floor. You can easily see the carrier well above the noiise floor before you hear any audio. Say you need 4 bits of A/D to get any usable audio.
This now becomes 4 bits less dynamic range you can claim. Without a preselector there is additional noise into the A/D so the floor is higher knocking off more bits.
Take Flex and measure MDS and dynamic range just looking at the spectrum display (which shows impressive numbers) then do the same thing with an AC RMS meter on the audio as you would with an analog receiver.
My QSD is pretty close to the SDR1K and I found the noise floor drops when the bandwidth is limited ahead of the input. It is very easy to demonstrate great performance with two signals as an input but things degrade when there are 200 signals coming in to the QSD. That is why I'm still hanging off a 455 KHz IF.
The HPSDR (A,O,J) MDS sits at about -145 dBM buy I can only get -130 or so due to set up noise.
Presently it looks like the Quick Silver 2 is the machine and Phil told me he is still involved with HPSDR Mercury. I figure by summer there will be another performance jump. QSD, SDR1K and Flex 5K so yesterday. So don't spend a lot of money yet.
I look to the future to see the day when there is no longer LO phase noise to limit close in performance or DDS spurs to trash the WB spectrum. I hear there may be a 170 mHz A/D option possible. Not sure if the DDC can keep up with the flow though.
Staty tuned
 

[VE7 Kilohertz]

I wonder if my Collins HF-8060 preselector would be of value in front of the 6790 or HF-2050?  It was made for the HF-2050 and HF-8050 series of RX's.  I haven't got around to reading the manual to see what exactly it does, or what it needs for tuning input...but it's sitting in the rack.

paul

[WA1GFZ]

A preselector that is tuned is the way to go. I have a nice cubic one that I hope to press into service. It is tuned with 4 BCD inputs. The problem today is the same as in TRF days when receivers got dual RF stages. Harris also makes a nice one.
The Harris and Cubic pre/post selectors both have a 10% bandwidth

[WA1GFZ]

We have a couple R&S receivers in our lab. I would have to perform that test myself. One tunes from 30 hz to 40 GHz in one box. the other only goes to 7 GHz but has a built in tracking generator.
I know someone who bought a 3280 and likes it. They are 2 or 3 conversions to a DSP with many possible bandwidths. It may also have I/Q outputs if that isn't enough for you. The 3038 is a single control to dual analog RX. Good for diversity. I have a couple Cubics and would like to find the time to hot rod them. Very well built. A bit more phase noise than a Racal though.
I would put my money on the 3280 if you want it all in one box.

[The Slab Bacon]

Yea, someone told me to have an open mind. I tried it and my brain fell out.


Most people didn't notice.

Yea, but I can blame it on all of the drugs I did back in the 70s and get away with it!!

[WA1GFZ]

http://www.kongsfjord.no/

Check out the Dallas files. Good reading on the real performance of SDR. He is a little further up the food chain but we both agree.

[WA1GFZ]

Sounds like serial A/D data. I'm sure it could be easily converted to analog with the right pair of shift registers and a couple D/As with a little glue logic.

[WA1GFZ]

I read  it a while ago nice looking radio.....

[WD8BIL]

You must not have taken enough or they weren't very good drugs. YOU REMEMBER TAKING THEM!

That's most likely true, Mack.
But sometimes our memories are nothing more than our brains animation of what someone told us we did.

[WA1GFZ]

Phil Covington told me the the next faster A/D will drop right into his new RX and runs at 160 MHz. Sample rate. His radio sounds like it will be the hot rod soon.
Then there is the blank window with no date for the 250 MHz part of the future.
It will have 2 more bits than the Italian radio. I hope the price isn't too high.
Dallas sent me some test data on the Italian and Phil shared some of his test data.
No synthesizer phase noise is quite cool. Still there is the front end issue so worse case it make a cool converter hanging off an IF.

[WA1GFZ]

I will be getting real test data on the Perseus from a trusted source. I will share it as soon as the source tells me it is ok.
Each bit you add increases the dynamic range by 6 dB. The faster you sample the more data you have to play with.
Two digital streams are cool if you are a software guy and can suck it into a computer of DSP. A good software guy would deal with it. I'm thinking it could be sucked into a parallel port.

[Steve - WB3HUZ]

Each bit you add increases the dynamic range by 6 dB.

Only if everything else is right and only up to a point. Many computer sound cards claim 24 bit A/D. None have 144 dB dynamic range. Neither will any receiver.

Right now, Perseus is just vaporware. Until it can actually be purchased, all comparisons of it to items currently available are bogus.

[Steve - WB3HUZ]

HUZ, the Perseus can indeed be purchased now but it's a 'pay now' and maybe wait for months deal. The demand has just overwhelmed the manufacturer at this time, the next production run isn't forthcoming until February.

OK, right now, Perseus is just vaporware. Until it is actually being shipped with the SAME specs as are being claimed, all comparisons of it to items currently available are bogus.

[WA1GFZ]

Steve is very right on the bits, I was dreaming in a perfect world. Dallas plans to return his radio....after he collects some data. I'm not sure if Sherwood has this one yet. Heck send him an email he will respond. He is a good guy.
I think it will be safe to say Covington's design with 2 more bits will have greater dynamic range. I was on the Perseus site and looked at some of the displays and see the noise floor well raised before the spurs appear. I measure dynamic range as any increase in the noise floor or a spur generated which is real world. The S5 method is quite bogus but makes the sheep think they are getting something good.
Perseus guys claimed the noise floor was raised due to the generators but I'm not sure. 14 bits is 84 dB unless you do magic. 84 dB close in is pretty good but not so hot wide band. My QSD does 90 dB at 1 KHz spacing and 97 dB at 10 KHz.
It also chokes on anything stronger than -27 dBm. I'm using HPSDR interface.

[VE7 Kilohertz]

Success at last! Snagged the latest ebay auction on a Cubic CDR-3280 rcvr!   

217 posts later and the thread is back on track...a new record??  :-)

Congrats Mac!! Let us know how you like it when it arrives.

Cheers

Paul