Electronics > RF, Microwave, Ham Radio

Whatever Happened to Ham Radio?

<< < (150/150)

Here you don't get to play with your Bird meters.   


--- Quote from: bob91343 on December 04, 2021, 02:07:22 am ---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.

--- End quote ---

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.


A review on one of Icom's most popular pre SDR sets the IC-7000.


NOTE: If Craig had turned on the ANF 'auto notch filter' that interference would have been notched out!

--- Quote ---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
• 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

--- End quote ---



[0] Message Index

[*] Previous page

There was an error while thanking
Go to full version