[MRCA] Chicom Type 883 VHF radio

[Ray Fantini]

Fun facts about the Chinese Communist radio!, just looked over the schematic and although did not look at it in detail learned a couple things.
First, the transmitter only uses six transistors total! On carrier oscillator and the rest are amplifiers. There is a transistor that's external of the transmitter section that regulates the DC voltage to the HFO so maybe you can say there are seven.
Second,  in the PTT (Push to Talk) control line they have a couple electrolytic in series with the PTT relays that prevent the operator from talking too long, imagine  it's in place so that if you sat on the mic switch it would kill the transmitter and prevent jamming the frequency, or maybe the idea was that no field station would have anything to say beyond whatever the charge time of the capacitors is?
Third, no volume and no squelch. This is the first Chinese radio I have had the opportunity to look at and see they are employing the Soviet mindset of no volume and no squelch. The same thing you see in a lot of the Soviet sixties and seventies radios like the R-105 and R-107. The Russians at least used handsets so you did not have to listen the noise all the time but think the Chinese used a headset with this radio. Also the radio has only two transistors in the audio stage so it's not that loud to begin with.


Ray F

From: MRCA [mailto:mrca-bounces at mailman.qth.net] On Behalf Of DSP3
Sent: Wednesday, July 29, 2015 9:24 AM
To: mrca at mailman.qth.net
Subject: Re: [MRCA] Chicom Type 883 VHF radio

Ken,

I did an article in ER magazine a few years back on the model 884 FM radio.  They sound like they might be similar radios?  The issue was December 2006.  The 884 will just get inside 6 meters but no high enough for the military FM common frequency.  I had a pair of them and, although they did work, I found them to be really lacking.  I would also hear a lot of TV birdies on these.  Did yours come with a manual, I hope?

Jeep - K3HVG
On 7/29/2015 8:10 AM, Ken Downs wrote:

This past weekend I picked up a Chinese army backpack radio. It looked interesting, came with a bunch of accessories, and was priced right, so I took a chance inspite of not knowing anything about it. It turned out to be a type 883 VHF (45-50 MHz) FM/CW rig made in 1974. The model was used 1972-1980's and is all transistorized - no tubes or ICs.

Anyone have any experience with these radios? The receiver on this one sounds live, but does not receive anything. The TX also has no output. I replaced the T/R relay (it came with spares) but still no joy. At this point I suspect the LO or something in the multiplier chain. Any suggestions?

Worse come to worst, the great little case could be used for an HF QRP radio.

Thanks and 73,



Ken, W1KRT



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