I've had my pro 3 for several months now and really love it. If searching for the book ic pro 3 service manual in pdf form, then you have come on to the loyal website. I acquired the radio from a gentleman that found it in a storage auction so i am sure it sat for a few years in there not being used.
There are numerous other rigs here which get little or no attention now that the icom is part of the mix. I important read this instruction manual carefully before attempting to operate the transceiver. This in-struction manual contains important safety and oper-ating instructions for the ic If you prefer to be anonymous write it in the message. The mp3 audio clip below is an over the air recording of my ic pro iii running with external alc and processed audio, pro iii with external alc and audio processing on am size is kb - mp3 what the pro iii sounds like on am without the internal alc and internal audio.
This feedback will increase the 3rd-order intercept point and IMD3 dynamic range without loss of sensitivity when Preamp 1 is engaged. Employs new quad-JFET first mixer. The strong-signal performance of the mixer and its peripheral circuits is greatly improved. Uses a fundamental-type SMD monolithic crystal filter as the first roofing filter. The fundamental-type crystal filter, as opposed to a filter using 3rd- or 5th-overtone crystals, will have a better shape factor and be less susceptible to intermodulation under strong-signal conditions.
Daishinku is the filter supplier. View a typical filter data sheet. To satisfy my own curiosity, though, I ran a few quick receiver tests: MDS, reciprocal mixing noise and filter shape factors. The test setup was as follows:. The results obtained are very close to those in Ref. Reciprocal mixing occurs in a superheterodyne receiver when the noise sidebands of the local oscillator LO mix with strong signals close in frequency to the wanted signal, producing unwanted noise products at the intermediate frequency and degrading the receiver sensitivity.
Reciprocal mixing noise is a measure of LO spectral purity. In this test, a strong "undesired" signal is injected into the receiver's RF input at a fixed offset from the operating frequency. The RF input power is increased until the receiver noise floor increases by 3 dB.
The reciprocal mixing noise parameter, expressed as a figure of merit, is the difference between this RF input power and measured MDS. The test is run with the 2. The higher the value, the better. DSP-IF filter shape factors. Shape factors for all 3 filter settings met or exceeded Icom's advertised specifications. SHARP vs. Test conditions: This test was intended to measure noise reduction on SSB signals close to the noise level.
NR settings. The results are given in Table 4. This is an approximate measurement, as the amount of noise reduction is dependent on the original signal-to-noise ratio. As in the IC, the upper and lower -6 dB points of the transmitter audio-frequency response are independently programmable. This capability, along with the bass and treble equalisation menu, offers many intriguing possibilities.
Thus far, I have been using default settings, but plan to do more experimentation. As discussed in the ARRL Test Report, CW operators will be very relieved to hear that the "dit-clipping" problem which plagued the Pro2 in full-break-in mode has been completely eliminated from the Pro3. A quick check has confirmed this. It has been reported that the Pro2 NR's heuristic correlation-discrimination process correlated signals vs. Keying the transmitter reinitialises the NR process, creating a perception of improved NR efficacy.
I have a sneaking suspicion that the NR process in the Pro3 reinitialises itself automatically every 15 sec. This, added to the improvements in the receiver's RF chain, may explain the improvement in weak-signal handling with NR on as noted above. It knocks down the band noise by about 20 dB, but does cut the treble response somewhat as is to be expected.
The received audio in CW mode is much more pleasant to listen to, and less fatiguing, than on the Pro2 or Pro. This is particularly noticeable when using the narrow IF filters Hz and less. The low-frequency rumble reported in the Pro has been completely eliminated in the Pro3.
A: Yes, it certainly is. Let me start by remarking that my background in telecommunications engineering strongly influences my view of amateur radio.
From my perspective, the sole mission of an SSB radiotelephone communications system is to " get the message through " with the highest possible articulation index at the receiving station, under a wide variety of propagation conditions. Excessive transmitted energy below approx. In addition, the practice of "force-feeding" - deliberately boosting the low-frequency portion of the baseband - can drive the speech amplifier into non-linearity, generating harmonics which mix with the mid-band speech components to yield a rich harvest of intermodulation products.
These products "muddy" the transmitted audio. In extreme cases, excessive baseband input levels can over-range the ADC, with ruinous consequences for the modulation process. Just a low-frequency rumble was audible in the headset. Only by "slicing away" the low end with 2.
Desk microphone. Links Gytaxetelet. Checked Dr. No viruses. It all started with the ground breaking IC- The high resolution 4. Shipping Jusmin Instruction Manual. Repair Jvgavila. I got it with a known fault, consisting of powering up always on TX due to some damage in the ACC1 connector area. Unit came in original box, with manual , hand mic and cable. With Forums. Just Now The was a low-cost rig at the time, it was Icom 's answer to "the IC is too expensive, we want a downgraded model that costs less" and this is what they came up with.
But it had a lot of problems. Model Hampedia. Remove only two lowest diodes marks as D and D Reset is not necessary. Shipping Phvia Besttfile Besttfile Icom Pro III. Feb 28, New, old radio. Hint- it's an Icom. Bushmaster serial number manufacture date. Icom Radio News Number 5 1 of 2. L In manual mode, the heater output should be directly controlled by a …. Manual Forums.
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