Does anyone know of a 455kc upconverter?

[ke7trp]

Looking for a 455kC to 10.7 or other IF in the MHZ range so I can use the 455KC output of the R390 (and other receivers) with SDR radios.  I saw one and have misplaced the link. 

Any kits?

C

[WA1GFZ]

You can buy softrocks set up for 455kHz. An extra conversion stage will just generate more crud. HPSDR will also work down to 10kHz

[ke7trp]

I never thought about the crud. I guess that would be to the design of the converter.  I have seen one before but cannot remember the name of it. 

Is the softrock a  DDS receiver where it uses the sound card?    Dont want to do that really. Just want to run the R390 as the front end.  So I can set the R390 Wide, then use the SDR to clip out slop buckets and adjust bandwidth ect.

C

[WA1GFZ]

If you had a stand alone SDR then you would not need the R390. I started doing the same thing on the 455KHz output of my Racal. Then as time went on I was able to eliminate the need for the Racal. You need the computer for th edisplay and a WAY TO CONTROL THE sdr. The computer will not be required someday.

[K3YA]

You can buy softrocks set up for 455kHz. An extra conversion stage will just generate more crud. HPSDR will also work down to 10kHz

I was looking for a softrock for the 455 IF on my R390, but couldn't find one.  It appeared that they are NLA and the current products are more complex and expensive.  Is there a source for the simple ones tuned to 455 IF?

[ke7trp]

I have an SDR receiver.  The problem is that alot of them do not have filters.  So the BC band takes them out.  The SDR I have wont go to 455. So I was just looking for a way to add the SDR to the R390.. This way, I have the R390 front end and can have the scope and notch of the SDR. 

As far as I know, The 455KC Softrock is acient history.   So I think there is a need for a 455kc up converter.  10.7 is popular and is in the range of any SDR. 

Most new radios like the yaesu line now have IF out at 10.7 with the idea that you will hook a scope or SDR radio to the jack.  Its listed in the adds.  I did this with my FT101 and it worked FB. 

C

[W3RSW]

My SDR is good even with BC band.  Don't live in a high BC field density area.  So if you can get by without clipping, BC signals act as dither thus enhancing SDR.

A decent BC band filter if required can be built with three toroids and a few capacitors. A single signal block for the local 50k'er down the road is even simpler.

A good SDR will exhibit brick wall and infinitely variable bandwidth filtering.

[Steve - K4HX]

You don't need a Softrock if connecting to an IF. Any downcoverter will work. There are numerous designs and probably kits on the Web. Do a search for DRM downconverter.

Here's one.

http://mysite.verizon.net/sdp2/id12.html

You can buy softrocks set up for 455kHz. An extra conversion stage will just generate more crud. HPSDR will also work down to 10kHz

I was looking for a softrock for the 455 IF on my R390, but couldn't find one.  It appeared that they are NLA and the current products are more complex and expensive.  Is there a source for the simple ones tuned to 455 IF?

[WA1GFZ]

Check Softrock again Tony was talking about them a few weeks ago on his site. The R390 preselector would make a nice SDR front end but all the rest of th emixers and IFs just add to degrade performance

[ke7trp]

Steve, Thats a down converter. Thats not going to work.  An up converter would take the 455KC IF and put it in the HF band so you can tune the SDR to the Radios IF.  ESP makes a down converter but that is for sound card use. 

C

You don't need a Softrock if connecting to an IF. Any downcoverter will work. There are numerous designs and probably kits on the Web. Do a search for DRM downconverter.

Here's one.

http://mysite.verizon.net/sdp2/id12.html

You can buy softrocks set up for 455kHz. An extra conversion stage will just generate more crud. HPSDR will also work down to 10kHz

I was looking for a softrock for the 455 IF on my R390, but couldn't find one.  It appeared that they are NLA and the current products are more complex and expensive.  Is there a source for the simple ones tuned to 455 IF?

[K3YA]

Check Softrock again Tony was talking about them a few weeks ago on his site. The R390 preselector would make a nice SDR front end but all the rest of th emixers and IFs just add to degrade performance

Thanks.  I found a "SoftRock Lite II"  available for a 455 IF at Fivedash.com and ordered it.  Now officially on my list of unfinished projects.

[ke7trp]

Let us know when you get the kit and what you think of it please.

C

[Steve - K4HX]

For your requirement, that is correct. I was answering K3YA. For you, check around the LF crowd. In years past they used many different up converters that block up converted 0-500 Khz or so to one of the ham bands. I used to have one that came with an E-field probe (active rod antenna). It's not much different than the circuit at the link I posted except the LO freq is set for up conversion. Here's a typical ham example.

http://ve1zacradio.antserve.com/A%20LF%20UpConverter%20forthe%20K9AY.htm

Or try this kit and be sure to get the higher cutoff freq option.

http://wb9kzy.com/lfconv.htm

Steve, Thats a down converter. Thats not going to work.  An up converter would take the 455KC IF and put it in the HF band so you can tune the SDR to the Radios IF.  ESP makes a down converter but that is for sound card use.  

C

You don't need a Softrock if connecting to an IF. Any downcoverter will work. There are numerous designs and probably kits on the Web. Do a search for DRM downconverter.

Here's one.

http://mysite.verizon.net/sdp2/id12.html

You can buy softrocks set up for 455kHz. An extra conversion stage will just generate more crud. HPSDR will also work down to 10kHz

I was looking for a softrock for the 455 IF on my R390, but couldn't find one.  It appeared that they are NLA and the current products are more complex and expensive.  Is there a source for the simple ones tuned to 455 IF?

[KF1Z]

There should be plenty of comments here already on that kit.

A search of posts here for " softrock lite "  should get you some information.

"fivedash.com"  is just Tony Parks' KB9YIG ( designer of softrock) new website.

[ke7trp]

Those use the sound card.. I dont want to use the sound card. I want to just hook my USB SDR radio to the IF of the R390A and have it look at the IF passband set on wide. 

Steve, Thanks for the information, I am thinking this might work

http://www.cliftonlaboratories.com/jackson_harbor_press_vlf_converter.htm

[Opcom]

every cheap am-fm transistor radio has the right crystal for the job and probably the transformers too.

[Steve - K4HX]

The Clifton Labs link is just this converter.

http://wb9kzy.com/lfconv.htm

Those use the sound card.. I dont want to use the sound card. I want to just hook my USB SDR radio to the IF of the R390A and have it look at the IF passband set on wide. 

Steve, Thanks for the information, I am thinking this might work

http://www.cliftonlaboratories.com/jackson_harbor_press_vlf_converter.htm

[ke7trp]

Thanks. I guess the guy gets alot of email for that converter. It turns out he just reviewed the product and does not sell it.  He got mad at me for emailing him


C

[Opcom]

I like angry responses to polite inquiries. They always end up on the www and rank top in Google.

[WU2D]

That would not be a hard project if you wanted to build something.

Just grab a crystal oscillator like this 12 MHz job. http://www.ebay.com/itm/Crystal-Oscillator-12MHz-Abracon-/110620365612?pt=LH_DefaultDomain_0&hash=item19c17cd32c#ht_500wt_1180


And a mixer of some kind like this: http://www.ebay.com/itm/Lot-of-3-Mini-Circuits-TUF-1-Mixer-Level-7-/290766971703?pt=LH_DefaultDomain_0&hash=item43b30fe337#ht_500wt_1414


12 MHz + .455 = 12.455 MHz where you would tune the SDR.

You would need a buffer amp to drive the mixer like a 2N2222A or two (matching the 455 output impedance to the 50 Ohms of the mixer) and you would also need a post amp for after the mixer like a little 50 Ohm Amplifier job like this http://www.ebay.com/itm/Mini-Circuits-Monolithic-Amplifier-MAR-1-/290738261371?pt=LH_DefaultDomain_0&hash=item43b159cd7b#ht_715wt_1164

And some filtering but basically that is about it to make an upconverter for 455 kHz.   

Mike WU2D

[ke7trp]

This product here is exactly what I was looking for but its for a different frequency

170906328510  On EBay


SDR goes into one port,  Output on 100mhz.  I emailed about a custom version.

C

[ke7trp]

Heros makes exactly what I was looking for. Its not cheap.  Nice products are not cheap.

http://herostechnology.co.uk/pages/VLF_LF_Converter.html


C

[ke7trp]

I got the up converter.  Its built well and works as it should.  PLus, I can use it for LF band which I have been enjoying. 

The R390 is a rebuilt unit with Chuck felton upgrades.  The R390 runs the IF out to the HERO's converter and then to my SDR radio.  I had to use an Attenuator between the R390 and Heros.  Once IF level was set, I tuned the SDR to 4.454.7 and it hit the R390 IF dead on. 

I have been listening to SSB and cannot detect any Drift.  Even after an hour, I did not have to adjust the R390 VFO. I was suprised the old girl is that stable. 

Performance?  I consider this to be the ultimate. It is the best I have used to date.  There may be better RX'ers out there but I dont think for my use (no CW) there would be a point to invest any money.

My main use is to knock out the slop buckets that intrude on AM round table.  The SDR can see a 20KC brick wall now with the R390 in play.  Then, I can set the bandwidth to what ever I want from the SDR.  SSB is very smooth with the R390 set to slow. Of course the display is awesome and the Knotch filter's are great for knocking out the Noise.

Now, I am going to move forward in designing and enclosure for the SDR, audio amp, Heros, Flat panel and small computer(terminal?)

I cant stand having to use my Laptop  in order to use the radio and I cant stand using headphones.  I get a headache within 20 minutes.  If I can build this into the rack or a small rack case and have this routed to a good speaker, I will use this setup alot for years to come.  If not, I dont think I am going to use it much as I will have to drag out the laptop just to relax and enjoy some AM.

C

[Steve - K4HX]

Take a look a the single board computer (gumstix or similar). These might be able to serve as your SDR controller, eliminate the laptop and fit in a rack.

[ke7trp]

Thanks.. I cant remember the type that robert uses for his SDR. He described them as a windows all in one computer. Very small and cheap.  The idea is a wireless mouse on table,  Small PC, Heros, SDR all behind on rack shelf with a rack mount Flat panel over the top of the R390. A small rack mount preamp, eq, audio amp (found several on amazon)  I can set it to auto boot and run HDSDR and play when I turn the power strip on.  Should be awesome FULL HiFI AM sound.  Jays performance test blew me away of the softrock and R390A setup


C