Not so simple, though. Look at air band VHF communications, still in good old AM.
My understanding is that aviation VHF uses good old AM because a weak signal is less likely to be obliterated by a stronger one. There's no "capture effect" with AM. But this doesn't explain why marine VHF is FM, so perhaps this is just an old wives' tale?
Not so simple, though. Look at air band VHF communications, still in good old AM.
My understanding is that aviation VHF uses good old AM because a weak signal is less likely to be obliterated by a stronger one. There's no "capture effect" with AM. But this doesn't explain why marine VHF is FM, so perhaps this is just an old wives' tale?
Yes, that's correct regarding airband AM. Moreover, as control towers have some carrier offset you will hear a beating tone if an aircraft transmits at the same time. By using offset carriers for control transmissions it also exploits a cheapo "voting" system. So it has several benefits. But think about the cost and complexity of replacing it with a more modern digital scheme.
As for marine VHF, same thing. Simple and cheap.
Very nice!
Thank you. I just had it on last week. I have other vintage SW receivers and I wanted to listen to them for a retro experience, make sure they all still work. It still works fine and sounds good.
40 years ago that would have been on my wishlist as an aspiring Novice. I probably should have gotten the lower priced R-600 model or even the lower end Radio Shack receiver on the market at the time, but I went another direction with the Heathkit SW-717. What the SW-717 lacked in capability it made up for by teaching me what a lousy/poorly designed "receiver" truly was. I wasn't done yet as I bought a couple more Heathkits before learning my lesson. 
Funny you should mention the R-600. I just recently within the last month got an R-600 which I had been wanting for a while. It was on Ebay in a city not too far from me so I went ahead and bid on it. The picture looked extremely clean, so why not take a chance? Well I won the bid and when I got it I was shocked. The thing looked brand new and I do not exaggerate. Like right out of the factory box. The inside was immaculate, not a spec of dust. How could this be? Where did the seller get it? This is what she told me when I asked her where it came from -
"My father (who was not a ham radio operator) died in September. He was a hoarder, being brought up in the depression he didn’t throw things out because you might need it some day. Anyway, I was cleaning out his van and found it.
No one (my mother or sister) even knew he had it, let alone why. My guess is he bought it new, thinking he might need it and never did.
I am so happy it’s in such wonderful condition. I was married to a ham radio operator and was the only one who even knew what it was.
Enjoy!!"
Pictures below but they won't do it justice.
I have a R1000, too, & a sweet looking receiver it is!
I had, (& used a lot), a Drake SSR1, which is now languishing in the "round tuit" box.
The Drake is quite "agricultural" in appearance, compared to the Kenwood, but, in my estimation is a better radio, as the Wadley Loop analogue design allows tuning in much smaller increments.
Don't get me wrong, though, the R1000 is still a nice radio.
Back to "hamming", I currently have no working 13.8v power supply & need to finally get around to fixing the broken one!
As with many hams, radio takes a back seat to other more urgent stuff, so you mainly come into contact with those who have "got their act together" enough to have additional funds, time & space, the fanatics, who don't care about anything else, the "whackers", or the "preppers".
It is a bit like EE & IT people----most people think some young twat who developed a totally unnecessary "App" for iPhones is an "electronics genius", & that "hackers" are agents of Satan!
I have an original Collins not a clone, R-390. No bloody A, B, C or D.
It'll beat all that solid state stuff in performance.
The problem is lifting it into a rack!
And it's still is not for sale..
http://www.r-390.com/ <---- Not my page, but look at those filters.
https://en.wikipedia.org/wiki/R-390A <---- A
Here, the small brother Collins 51 S-1 desk model...Have the KWM-2 too.
R-390 was on my wish list but the size is not the favor one....
At one point I owned three R-390A receivers. I did a few modifications and at the time I thought it was the greatest receiver out there. If you limit your contest to tube radios, it wins on every level.
That being said, it is eclipsed by my TS-940S. Not as great a selection of bandwidth, but nearly everything else is better on the Kenwood.
Speaking of the R-600/R-1000, some years back a local dealer I know well had one or the other on his table at the state convention. I walked by it a few times but did not buy it. It would have been nice nostalgia, but I'm really more interested in transceivers these days. In mid 2014 I bought a TS-520SE off eBay with the narrow CW filter, very clean and it aligned nicely. I've since added the DG-5 display, and remote VFO and speaker. It's a nice classic setup.
Earlier this year I bought a TS-130SE from a local. I need to go through it and touch it up before Straight Key Night. That gives me just over a month to get that done!
Otherwise, I've been tinkering with this and that.
I was lucky a year or two ago when I got a pristine TS-520S with manual from an old guy (ha! I'm older than he!) who had bought it new in 1975. It works great. He said the finals had less than 5 hours on them.
I added a homebrew digital display using arduino; all external, no mods needed to the radio.
A thermal shot of the R-1000.
Wahoo!---I just had a contact on the local 2m repeater with VK6ATX mobile, using the old Yaesu FT411 I picked up, (along with a 2m "brick" RF amplifier, & a couple of small power transformers), for $A50, a couple of Hamfests ago.
The FT411's Nicads had, of course, "gone to battery heaven", but I managed to remove them after a bit of butchery, temporarily replacing them with 2 little PP3 9v Alkalines.
Up to now, because of the non-rechargeables, I have been limiting use of the radio to calling in after the weekly "ham news", so this is its first longish contact.
The 2m repeater is usually dead silent, so it was a nice surprise to hear him calling.
I think I've got the ham virus back, so I will really have to get back into "fix it" mode so I can use the stuff that needs my (currently dead) power supply!
Maybe even fix some non-ham stuff!!
At one point I owned three R-390A receivers. I did a few modifications and at the time I thought it was the greatest receiver out there. If you limit your contest to tube radios, it wins on every level.
That being said, it is eclipsed by my TS-940S. Not as great a selection of bandwidth, but nearly everything else is better on the Kenwood.
can you be more specific? I wanted a r390a for a while and I was interested in how it compares to modern radios. I guess the newer radio is more sensitive? I am wondering what the limiting factors are, since with HF it is normally not noise I think (since atmospheric noise dominates when a real antenna is connected to the system).
The R-390A is a fine radio. It's big and heavy and runs very warm. Its mechanical construction is complex and needs occasional service.
The speaker impedance is such that one needs an external transformer to drive most speakers. The S meter is not calibrated in S units, a minor annoyance. I don't recall the antenna input impedance, whether 50 Ohms is an option or not.
The frequency stability is not up to modern standards; a long warmup is a good idea. Nor is the frequency resolution, with one dial division each 200 Hz (vs most modern radios with 10 Hz or even 1 Hz steps). If I remember correctly, switching from USB to LSB requires some juggling of tuning and BFO dials. CW seems to require yet a different setting.
I changed mine over to solid state rectification to eliminate the hot rectifier tubes.
Those are the main shortcomings. As for convenience, changing frequency is a major chore, especially large frequency jumps. If you are on 75 meters and want to QSY to, say, 20m CW, there is no way to do that quickly. There can be annoying backlash of the dial, causing differing readings depending on tuning direction. If you are an SWL, going over the hump at each MHz can really be a pain.
The audio CW filter and the wide selection of bandwidths are a definite plus. Sensitivity is not an issue, as the incoming noise level swamps the internally generated noise and there is plenty of gain.
When I got rid of mine, I felt a pang of regret. Now, years later, I don't look back.
Started with an Icom IC-7000 and an Icom AH4 auto tuner.
My old ears then needed a West Mountain Clr/dsp and a BHI NEIM1031. The noisy power line internet needed an MFJ1026 diversity phaser. Then came dstar and c4fm for the solar minimum.
The endfed 8010 half wave 80m at 12m was put up 7 years ago for QRP and gets into the US and UK depending on conditions.
Great hobby just treated as a hobby and a bit of fun! 3,000+ QSO's for a previous long term SWL. Got my lic. after the internet killed SWL and the commercial hf bands went silent!
My current radio desk layout using glass tv shelves...
Scherms, that's a good visual example of how the hobby has evolved.
Too bad the average person is unaware of the great innovations happening in ham radio today. Instead, they assume it's a dead & obsolete hobby.
We’re aware of the innovations. They’re just a bit, well, meh.
I’m talking to you in the US via a web site hosted in the US from the UK set up by a dude in Australia. And not once have I had to worry about cycle 25 propagation or say CQ
We’re aware of the innovations. They’re just a bit, well, meh.
I’m talking to you in the US via a web site hosted in the US from the UK set up by a dude in Australia. And not once have I had to worry about cycle 25 propagation or say CQ
But HF has nothing to do with conversation. It's like fishing, you get nibbles and then a bite! Bag it and move on. It's a jungle jumble... thats what makes it great.
iPhone does everything else...
It's like fishing, you get nibbles and then a bite! Bag it and move on. It's a jungle jumble... thats what makes it great.
Same thing happens here and it's thousands $$$ less expensive.
Here you don't get to play with your Bird meters.
The R-390A is a fine radio. It's big and heavy and runs very warm. Its mechanical construction is complex and needs occasional service.
The speaker impedance is such that one needs an external transformer to drive most speakers. The S meter is not calibrated in S units, a minor annoyance. I don't recall the antenna input impedance, whether 50 Ohms is an option or not.
The frequency stability is not up to modern standards; a long warmup is a good idea. Nor is the frequency resolution, with one dial division each 200 Hz (vs most modern radios with 10 Hz or even 1 Hz steps). If I remember correctly, switching from USB to LSB requires some juggling of tuning and BFO dials. CW seems to require yet a different setting.
I changed mine over to solid state rectification to eliminate the hot rectifier tubes.
Those are the main shortcomings. As for convenience, changing frequency is a major chore, especially large frequency jumps. If you are on 75 meters and want to QSY to, say, 20m CW, there is no way to do that quickly. There can be annoying backlash of the dial, causing differing readings depending on tuning direction. If you are an SWL, going over the hump at each MHz can really be a pain.
The audio CW filter and the wide selection of bandwidths are a definite plus. Sensitivity is not an issue, as the incoming noise level swamps the internally generated noise and there is plenty of gain.
When I got rid of mine, I felt a pang of regret. Now, years later, I don't look back.
I don't like the backlash thing.
For a long term project, do you think its possible to replace some of the mechanical hardware to make the adjustments more stable/accurate ? Some of this sounds like stuff related to worn gears and low quality screws? I am guessing someone (designer) got 'clever' with bent metal etc, and it does not work as it ought to. Like that stampings and whatnot were used instead of machined parts.
Check out this radio: SDR, nice display, 10W, HF-50 MHz coverage. But wait, there's more! Bluetooth (for keyboard and mouse), WiFi, USB in and out, antenna tuner, built-in battery. *And* you can run linux on the SAMD processor. Some hams have loaded WSJTX, JS8Call, and other programs on it, as well as VNC and other tools. It is now a completely self-contained HF digital communications rig.
https://www.amazon.com/Xiegu-Transceiver-Supports-Bluetooth-Screen/dp/B09PHK6XPB
A review on one of Icom's most popular pre SDR sets the IC-7000.
https://icomuk.co.uk/files/icom/PDF/productLeaflet/IC-7000.pdf
NOTE:
If Craig had turned on the ANF 'auto notch filter' that interference would have been notched out!IC-7000 HF/50MHz/VHF/UHF mobile transceiver (Discontinued)
Stylish and compact, the IC-7000 is the first radio in its class to have IF DSP. In fact, with features such as digital IF filter, digital twin PBT and manual notch filter the IC-7000 offers unparalleled performance not seen in a radio in this class before. Usability has also been enhanced with the incorporation of a 2.5 inch colour TFT display, eight direct access buttons and a detachable head for vehicle mounting. In short, the IC-7000 symbolises great leaps in performance, features, operability and design.
2 x DSP
There are two times the DSP in the IC-7000 that will leave many base station rigs in the noise! While it is too early to list all the great features, here are a few to keep you talking!
Improved AGC loop performance
With Multiple AGC loops, you will never experience AGC pumping from a signal filtered out by the DSP! The digital IF filter and manual notch filter are included in the AGC loop, so you will never encounter AGC blocking. IC-756PROIII and IC-7800, middle, fast for each operating mode.
Digital IF filters
All the filters you want at your fingertips! You will never have to purchase Optional filters as the IC-7000 has 41 different filter widths. You just dial in the width you want and select whether you want a sharp or soft filter shape for SSB and CW modes. Then to pull-in the weak ones, a quick turn of the concentric twin PBT knobs, allow you to either narrow the IF passband, or shift the entire passband to eliminate the QRM.
2 x MNF (Manual Notch Filter)
Pull out the weak signals in crowded band conditions with Icom's NEW two-point MNF manual notch filter. Apply 70 dB of rejection to two signals at once! Notch width is adjustable ¡V wide, medium, and narrow ¡V and an auto-tuning notch filter is available, too.
Digital voice recorder (DVR)
Record your callsign, CQ, or other information in 4 transmit playback memories with alphanumeric labels. A total of 90 seconds is available for the four memories. A front panel REC control allows you to record incoming signals, too! The DVR makes portable contesting or mini-expeditions a breeze!
Flexible installation with detachable panel
Smaller than the IC-706MKIIG, the IC-7000 measures only 167(W)x58(H)x180(D) mm*1. With the detachable front panel*2 many installation possibilities are available.
Remote control Microphone
The supplied HM-151 remote control microphone allows you to control often used functions of the IC-7000. This includes band hopping with Icom's Triple Band Stack registers.
2-mode band scope
The band scope function lets you watch conditions around the band. In Centre mode the band scope is centred on the receiving frequency. In Fixed mode the band scope sweeps a fixed range.
2.5-inch colour TFT display with TV screen receive capability
The IC-7000's display presents numbers and indicators in bright, concentrated colours for easy recognition. You can choose from 3 background colours and 2 font styles to suit your preference. Not only does the display provide radio status, but you can watch NTSC M or PAL B on VHF-TV channels!*
One-touch operation
Eight of the most-used radio functions are controlled by dedicated function keys grouped around the display for easy visibility. One quick touch turns the function and off. A longer touch activates adjustment of the functions setting.
Memory Keyer
The internal memory keyer provides 4 memories for station information or contest exchanges, calling CQ and call sign with up to 55 characters for each memory. The keyer also performs automatic repeat and automatic contest serial numbers.
IC-7000 Additional Features
• Selectable main dial tension from heavy, light and click
• SWR graphic display
• CW full break-in
• CW receive reverse
• CW pitch adjustable, linking to side tone
• Tone squelch in FM mode
• 503 memory channels
• Built-in voice synthesiser
• Duplex mode and auto repeater function
• Transmit monitor
• DTMF monitor
• 1Hz tuning
• CI-V interface
• RIT/∆ÝTX
• VOX
• RF/SQL knob
• Large speaker
• Thermo control silent cooling fan
• Auto TS function
• Noise squelch and S-meter squelch
• Preamplifier
• Dial lock
• Attenuator
• 35W output on 430/440MHz band
