{"id":868,"date":"2015-02-01T14:46:21","date_gmt":"2015-02-01T13:46:21","guid":{"rendered":"http:\/\/dc2wk.schwab-intra.net\/?page_id=868"},"modified":"2015-02-01T19:01:25","modified_gmt":"2015-02-01T18:01:25","slug":"the-repair-of-a-completely-destroyed-kenwood-tr-2300","status":"publish","type":"page","link":"https:\/\/dc2wk.schwab-intra.net\/?page_id=868","title":{"rendered":"The Repair of a completely destroyed Kenwood TR-2300"},"content":{"rendered":"

On a local Ham Radio Flee Market I saw for 5 or 10 \u20ac a\u00a0Kenwood TR-2300 QRP 2m portable station. It was no batteries pack in, no manual, and it was no microphone with. I don’t know it’s working or not. But this old TR-2300 are sold on eBay for up to 80\u20ac in good condition and without batteries. So I bought it.<\/p>\n

At home I saw that this radio was\u00a0completely destroyed. Some IC’S and transistors fail out of the radios, as soon I opened it. So a long repair is starting…<\/p>\n

\"IMG_3218\"<\/a><\/p>\n

At first I start to replace the parts on the upper side (with the speaker)
\nI saw that the voltage regulator (7805) was broken and the full 12 V came to the IC’s.
\nIt was a little 78L05 (smallest one with 100mA) what I replaces with a big 78S05 with 2A. I cut off the cool sheet, so it fits in. That regulator don’t broke any more. I replaces the other little transistors in that area. Then I replaced the Audio IC (UPC575C2), after that I hear the first rush again out of the speaker. But no station and no output. The final i let in in this time. It was to early to change that, so far.<\/p>\n

\"IMG_3215\"<\/a>
\nThen I checked all the frequencies around the PLL circuit. No Frequency was measurable.
\nAt first I changed the IC in the right. But that doesn’t help.
\nSo the PLL IC was broken too. That was very hard. The original was a SM5104GA. It was not to buy any more. I saw sone for big money in eBay, but that was me too expensive.
\nAfter some days in the internet I found a 12,5 KHz modification from UK, where the PLL is replaced with a MC145106, that I got from China for 6\u20ac with shipping. So nice, I got a PLL and 12,5 KHz modification.<\/p>\n

\"IMG_3217\"<\/a><\/p>\n

After 4 weeks the MV145106 is arrived. I solder the old PLL out and I saw that the new one is bigger and has more feet. I read again the modification and I know now, what I have done to me \ud83d\ude42 Cut Pin x to y off and solder it on the place z, and so on…<\/p>\n

\"IMG_3227\"
\n<\/a>Detail view of the new PLL<\/p>\n

\"IMG_3224\"<\/a><\/p>\n

It take 4 hours to build this PLL in. But after that I have the frequencies at the check points.<\/p>\n

\"IMG_3221\"
\n<\/a>For the switching of the +12,5 KHz, I use the AUX Switch.<\/p>\n

After a complete alignment of the PLL and the receiver, I hear my first stations on 2m.
\nI made a break for some days and enjoy the moment. But no output in transmitting, so far.<\/p>\n

I checked now the final transistor. He was broken too. So I find one in UK for 12,74 \u20ac with shipping. After the replacement and alignment of the transmitter, 1,5 Watts with batteries and 2 Watts with power supply came out. I was very happy \ud83d\ude42<\/p>\n

I tried to make a QSO on 145.700, but the frequency on the channel switch was not the same what I saw on my frequency counter. But the most off the channels was OK.
\nWhat happens now?<\/p>\n

I find out that the resistor network (under the PLL) was broken. So I removed it ad tried it with out. Damn it works \ud83d\ude42<\/p>\n

\"IMG_3228\"
\n<\/a>And kow I need a batterie box. I find one by Pollin for 1 \u20ac what fits in the place in the TR-2300. The accumulators are 1.2V 2500 mAh.<\/p>\n

\"IMG_3214\"
\n<\/a>As microphone I take a Peiker Mic, out of my box.
\n<\/a><\/p>\n

I made today (01.02.2015) my first QSO’s on a local frequency. It was great ! The receiver is very sensible and the modulation is clear and loud.<\/p>\n

Here you can download the 12,5 KHz modification for the TR-2300:\u00a0TR2300-12k5-step-mod-GB<\/a><\/p>\n

Here you can download the service manual for the TR-2300:\u00a0TR2300_serv<\/a><\/p>\n

That was the costs for the repair:<\/strong>
\nAccumulators (Pollin) 12,50 \u20ac
\nBatteriebox (Pollin)1,00 \u20ac
\n78S05 (out of my box) 1,00 \u20ac
\nother parts\u00a0(R,C,Tra.) (out of my box) 3,00 \u20ac
\n74LS73 (Ebay) 0,80 \u20ac
\nMC145106P PLL (eBay China) 6,00 \u20ac
\nIC UPC575C2 (EBay) Audio 4,45 \u20ac
\n2SC2329 Final\u00a0(EBay UK) 12,74 \u20ac<\/p>\n

Together: 41,50 \u20ac, so I got a TR-2300 for a little over 50 \u20ac and I had a lot of fun with the repair. That’s OK for me.<\/p>\n

But the work, you can’t pay.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

On a local Ham Radio Flee Market I saw for 5 or 10 \u20ac a\u00a0Kenwood TR-2300 QRP 2m portable station. It was no batteries pack in, no manual, and it was no microphone with. I don’t know it’s working or … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"_links":{"self":[{"href":"https:\/\/dc2wk.schwab-intra.net\/index.php?rest_route=\/wp\/v2\/pages\/868"}],"collection":[{"href":"https:\/\/dc2wk.schwab-intra.net\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/dc2wk.schwab-intra.net\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/dc2wk.schwab-intra.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dc2wk.schwab-intra.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=868"}],"version-history":[{"count":10,"href":"https:\/\/dc2wk.schwab-intra.net\/index.php?rest_route=\/wp\/v2\/pages\/868\/revisions"}],"predecessor-version":[{"id":907,"href":"https:\/\/dc2wk.schwab-intra.net\/index.php?rest_route=\/wp\/v2\/pages\/868\/revisions\/907"}],"wp:attachment":[{"href":"https:\/\/dc2wk.schwab-intra.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=868"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}