My first serious receiver was a used National NC 173 I bought from Lafayette Radio in Syosset NY. Plenty of paper route money. Today I still have a surplus R 392 which is similar to the old Collins R 390. 500 KHz to 32 MHz. I had a simple dipole till the old weeping willow tree had to go. Haven't fired up the R 392 in years but last time it was working fine. Like most Collins post war stuff it's a mechanical nightmare. Really good receiver though. When I got that R 392 they were $69 through Fair Radio Sales here in Ohio and I wish I had bought 3 or 4 of them seeing what they go for today. Every now and then Fair Radio comes up with good surplus stuff.

Ron

 

I expected to see some Yaesu or Icom receivers suggested. ¿?

BTW, when starting as a ham with my laboriously built AM xmtr (CW modified for voice in the 80/40 m band) I was lucky enough to get an old Collins rcvr from the WWII times still fitted with the anti rolling harness including the rubber fittings intact. Incredibly heavy (maybe 30 Kg or more).

I even could listen crystal clear, SSB using the BFO.

Many years later, I bought an incredible Yaesu FT901DM but the magic of achievement, was lost. Button pushers, way too many in the air.

 

I expected to see some Yaesu or Icom receivers suggested. ¿?

BTW, when starting as a ham with my laboriously built AM xmtr (CW modified for voice in the 80/40 m band) I was lucky enough to get an old Collins rcvr from the WWII times still fitted with the anti rolling harness including the rubber fittings intact. Incredibly heavy (maybe 30 Kg or more).

I even could listen crystal clear, SSB using the BFO.

Many years later, I bought an incredible Yaesu FT901DM but the magic of achievement, was lost. Button pushers, way too many in the air.

All of my VHF/UHF radios are Yaesu, my HF rig is Kenwood, but for BCB DXing, Tecsun and Sangean radios are best value, there is also Crane, but they don't make the radios just brand them.

 

on the intermodulation issue mentioned before.
An example of filtering in order to bring out a buried WWV time signal and what that looks like on SDR, the usefulness of filtering vs just sensitivity.
In the video at about 7:00 minets there is 30 dB gain already, the WWV 2.85 MHz, with the filter switched in it shows the ability to cut through noise and intermod. Receive WWVB NIST to explore weak signal reception by using WWV broadcast as a weak signal test with SDR spectrum to show filter results. Likewise attenuating the RF pre-amp, inserting intermod filter and watching the SDR reciever can give a fair approximation of an antenna.
The sensitivity might be 5uV the SNR signal to noise ration, the rf low noise preamp 30dB, antenna might be 9dB, the intermod filter and possibly you may want an audio filter.

Your ears may want to filter the white noise and how to find a filter criteria for vintage like distorsion.

 

My first serious receiver was a used National NC 173 I bought from Lafayette Radio in Syosset NY. Plenty of paper route money. Today I still have a surplus R 392 which is similar to the old Collins R 390. 500 KHz to 32 MHz. I had a simple dipole till the old weeping willow tree had to go. Haven't fired up the R 392 in years but last time it was working fine. Like most Collins post war stuff it's a mechanical nightmare. Really good receiver though. When I got that R 392 they were $69 through Fair Radio Sales here in Ohio and I wish I had bought 3 or 4 of them seeing what they go for today. Every now and then Fair Radio comes up with good surplus stuff.

Ron

The R392 is indeed a good receiver, in the classic realm. The tubes are still all available at reasonable prices, as well. But it may take some switch cleaning work if an unused surplus one can even be found. Many of those mil surplus receivers are still around, check out Fair Radio in Lima Ohio for an honest seller. Not cheap, but honest.

 

My first serious receiver was a used National NC 173 I bought from Lafayette Radio in Syosset NY. Plenty of paper route money. Today I still have a surplus R 392 which is similar to the old Collins R 390. 500 KHz to 32 MHz. I had a simple dipole till the old weeping willow tree had to go. Haven't fired up the R 392 in years but last time it was working fine. Like most Collins post war stuff it's a mechanical nightmare. Really good receiver though. When I got that R 392 they were $69 through Fair Radio Sales here in Ohio and I wish I had bought 3 or 4 of them seeing what they go for today. Every now and then Fair Radio comes up with good surplus stuff.

Ron

Lafayette Radio Electronics, I spent a lot of time there as a kid. I loved that place. I was living in Laurelton at the time. Wow, I hadn't thought of Lafayette in a long time... and Allied...

 

I still have my Knight Kit Space Spanner that I built when I was 11 years old. Sitting on the shelf waiting for me to resurrect it. I bought a used Lafayette BCR-101 at a Ham Fest and it was not very good. I always thought Lafayette had a good rep but later finding reviews on the net it was apparently not one of their proudest moments. First Ham rig was the venerable Heathkit HW-101 that I bought used. Realigned it a few times, swapped out some caps the original builder used the wrong value for, retubed the 6146 finals, and worked the world @100W with it on a multi-band dipole with traps and 3 element 10M beam. Always drooled over the Yeasu with the solid-state front end and 6146 tube finals.

 

The R392 is indeed a good receiver, in the classic realm. The tubes are still all available at reasonable prices, as well. But it may take some switch cleaning work if an unused surplus one can even be found. Many of those mil surplus receivers are still around, check out Fair Radio in Lima Ohio for an honest seller. Not cheap, but honest.

Yeah, I linked to Fair Radio Sales. I had some spare tubes and I think an IF section. No clue where those parts are. With all my life travels for work I left armature radio decades ago. Maybe it's time to get back into it. So many changes I see over the years. Code is apparently gone. What they now call a Technician Class looks like what was once a Novice Class since I no longer see a Novice Class. Also call signs were by region like New England states were 1 land and NY where I was was 2 land. CA was 6 land and Hawaii was like a KH6 land. Now all the call signs seem strange to me. I have an old friend in Rhode Island (our dads grew up together) and we both got our then Novice tickets in 1963. He is still active and more back into it since retiring.

Ron

 

Yeah, I linked to Fair Radio Sales. I had some spare tubes and I think an IF section. No clue where those parts are. With all my life travels for work I left armature radio decades ago. Maybe it's time to get back into it. So many changes I see over the years. Code is apparently gone. What they now call a Technician Class looks like what was once a Novice Class since I no longer see a Novice Class. Also call signs were by region like New England states were 1 land and NY where I was was 2 land. CA was 6 land and Hawaii was like a KH6 land. Now all the call signs seem strange to me. I have an old friend in Rhode Island (our dads grew up together) and we both got our then Novice tickets in 1963. He is still active and more back into it since retiring.

Ron

My grandfather was WA2EAQ, I still have my 1 land call from Boston.

 

My grandfather was WA2EAQ, I still have my 1 land call from Boston.

My dad was K2MKT and I still remember a few other call signs. I was WB2MHS but over the years and moves for the job I let it lapse. I was active in Iwa Kuni, Japan (Marine Corps Air Station) where we had the MARS network. I would guess my last activity was 1971. Retired now I really should think about getting back into it. I always enjoyed it.

Ron

 

Hello I justed retired after a heart attack and quadruple bypass surgery and I started a new hobby of listening to far stations so I need to purchase a new radio that works well on AM for this purpose. I know that you guys are experts in your fields and I am sure someone can help me.
Thank you very much for reading my question, all your suggestions will be greatly appreciated. Best Regards Michel

This was considered the best long range receiver for a long time. I found one at an estate sale one day, used it for a week or two and then sold it to a local radio enthusiast.

https://www.ebay.com/p/7044964904?iid=184642663299

 

For those who have been out of the hobby for a whle, some things have changed, some have not. There are now a lot of digital modes, some of them are able to get a message thru with the signal far below the noise level. Thatis amazing, really. And there are radios that are far beyond most imaginations, both in capabilities and complexity.
With the code requirement gone there are now a lot more extra class hams than ever before.
That technician license now requires mostly knowing rules and regulations, while the Extra class license now demands a fair amount of understanding allsorts of stuff, including the new solar flux nomenclatures.
THE massive proliferation of repeaters has altered VHF communication quite a bit..Lots of fun now.

 

Quiz - See if you can figure out why it reads 99.545?

It has to be 88.8; The IF is around 10.7MHz, so either add or subtract 10.7 for https://en.wikipedia.org/wiki/Superheterodyne_receiver

Add a frequency display: https://www.joom.com/en/products/5f22915ba4b5be010630dc4f

Someone built another http://theradioboard.com/rb/viewtopic.php?t=7647 for am/fm apparently. really hard searching for this stuff.

here https://www.audioamp.eu/digital-display-for-radio-receivers/ is another.

 

The most accurate frequency display circuit that I have seen used digital mixers to combine both the first and second local oscillator frequencies, and the BFO frequency, to display the exact frequency, after adding the BFO offset. There was also a mode to sample the actual final IF signal to read the exact carrier frequency.
There has to be a better way to add frequencies than was done using 7400-series TTL now that we have much faster logic available. The great thing about this scheme is that it would work with my KWM2A transceiver, which has a good calibration but not adequate resolution.

 

This thread sent me to check out the latest SDR offerings, not the cheap USB TV dongles, but devices designed for serious HF operation where digging tiny signals out of a crowded spectrum is imperative. I found this:
https://airspy.com/airspy-hf-discovery/
Has anyone any experience on it? It seems to be available for US$169 and has very respectable specs for the price:

Technical specifications

• HF coverage between 9 kHz .. 31 MHz
• VHF coverage between 60 .. 260 MHz
• -140.0 dBm (0.02 µV / 50 ohms at 15MHz) MDS Typ. at 500Hz bandwidth in HF
• -141.5 dBm MDS Typ. at 500 Hz bandwidth in FM Broadcast Band (60 – 108 MHz)
• -142.5 dBm MDS Typ. at 500 Hz bandwidth in VHF Aviation Band (118 – 136 MHz)
• -140.5 dBm MDS Typ. at 500 Hz bandwidth in VHF Commercial Band (136 – 174 MHz)
• -140.0 dBm MDS Typ. at 500 Hz bandwidth in the upper VHF Band (> 174 MHz)
• +15 dBm IIP3 on HF at maximum gain
• +13 dBm IIP3 on VHF at maximum gain
• 110 dB blocking dynamic range (BDR) in HF
• 95 dB blocking dynamic range (BDR) in VHF
• 150+ dB combined selectivity (hardware + software)
• 120 dB Image Rejection (software)
• Up to 660 kHz alias and image free output for 768 ksps IQ
• 18 bit Embedded Digital Down Converter (DDC)
• 22 bit Resolution at 3 kHz channel using State of the Art DDC (SDR# and SDR-Console)
• +10 dBm Maximum RF input
• 0.5 ppm high precision, low phase noise clock
• 1 PPB frequency adjustment capability
• Very low phase noise PLL (-110 dBc/Hz @ 1kHz separation @ 100 MHz)
• Best Noise reduction of the market using state of the art algorithms
• 2 x High Dynamic Range Sigma Delta ADCs @ up to 36 MSPS
• No Silicon RF switch to introduce IMD in the HF path
• Routable RF inputs with simple modification
• Wide Band RF filter bank
• Tracking RF filters
• Sharp IF filters with 0.1 dB ripple
• Smart AGC with real time optimization of the gain distribution
• All RF inputs are matched to 50 ohms
• 4 x Programmable GPIO’s
• No drivers required! 100% Plug-and-play on Windows Vista, Seven, 8, 8.1 and 10
• Industrial Operating Temperature: -45°C to 85°C
• Small Form Factor: 55 x 90 x 12 mm

I'm not quite sure what to make of the selectivity numbers.

here's a review:
https://airspy.com/downloads/TSM_Sep2019.pdf

and in the context of this thread, it would probably be a good AM DX receiver, if you want a PC based radio. I'd try to find a review by an AM DXer first though.

 

At a 500Hz bandwidth it would mostly be good for medium speed morse code. for analog speech to be sort of intelligible you need 2000Hz bandwidth, and 3000 Hz bandwidth for good intelligibility. And that is still nowhere near suitable for music. So that does sound like an interesting SDR package. Ido see that signa to noise ratio and audio distortion are not mentioned, conspicuous by their absence.

 

This is not a radio in the conventional sense, it does little channel filtering and no demodulation. What it does is digitise part of the RF spectrum and feed it to the PC for further processing. It outputs a stream of IQ samples via the USB interface. The widest bandwidth it can output is 660kHz (at 768kHz sample rate). The software in the PC then does an FFT on this and gives a spectrum analyser type display, and does signal processing to demodulate (AM, SSB, FM etc) any signal in this bandwidth. The bandwidth of the filters used are set in software, to typical values for these modulation types, but can usually be adjusted by the user to arbitrary values, dependent on the particular software. The IQ samples are 16 bits, which gives a notional 96dB of dynamic range of the signal fed to the PC for processing.

There is a review here that gives audio samples: https://www.fenu-radio.ch/Airspy_HF-Plus_Discovery-en.htm

I'm thinking about ordering one, but I'd have to get a tuning knob - it doesn't feel right to tune a radio with a mouse / keyboard.