Thanks!

Sorry, meant 15 meter band. My bad

It is an MM5221 1024 bit ROM (not an EPROM), organized as 256k x4 or 128k x 8 (user selectable). It is mask programmed in the factory, customized for CPI no doubt. The fact that it is mask programmed means it can not suffer "bit rot", a problem often associated with EPROMS. This means that if the chip fails nonetheless, it must be another, more rare occurrence. I have repaired many CP2000 radios and have never seen a failed ROM that was untouched. CB butchers like to "try out" ROM code converters to see if they can get more channels, so of you have seen a bad ROM I bet you it was the result of tampering from such an attempt. If the chip fails, it can be replaced by a much more common 6416 EPROM but it would mean a small conversion PCB is needed. If there would be enough demand for such a PCB, I would be willing to design one. Nice thing would be that it then becomes real easy to add another bank of 40 channels (or more), without tearing up the radio.

Well I have one with a warble on SSB receive. Maybe on XMT too. But no one has said anything. Looks like it was never hacked. It almost seems like it’s untestable locking on frequency? I noticed today the date code on 2) DM74160AN IC’s have a date code of 9310. CPI was history for more than decade. A friend of mine brought up some issue with the 74163 where later chips had issues with some older circuits. I any ideas? I noticed the shield is missing on the VCO coil and black group is surrounding where the silver mica capacitors are.

@@ronedwards8239 "9310" is not the date code, it is an alias for the 74160 TTL designation. These chips were made in the days that the TTL chip nomenclature was not fully established yet, I think Fairchild had their own naming convention, that's where the 9310 type coding comes from. But Texas Instruments won out eventually and the 7400 series naming convention was later established as the definitive naming convention. Which shows you how old these chips are in this radio; early Seventies. If you want to replace them you should pick from the 74HCT series; that is CMOS with TTL logic levels and are drop-in replacements that consume much less power. So you would replace the 74160 with the 74HCT160. The unstable PLL is probably caused by bad capacitors in the loop filter. You should replace them all.

I have replaced all electrolytic capacitors except a few on the power supply, amplifier and a couple tantalum’s on the front board with no improvement. Can you point out the capacitors you are referring to?

Do you know why the shield is missing on the SMO board on your radio?

Zeg maar nee dan krijg je er twee 🙂

They are both very good radios. But I like the 990 more because of its professional build using multiple plug-in cards on a motherboard. Easier to service and a very clean look. The FT-1000 does not have that, and as a result servicing that radio is a a bear. But the FT-1000 has dual receivers, a metal alloy (die cast) front panel and 150 watt RF output. So you be the judge...

@LifeIsTooShortForQRP still prefer 100 watt transistor power ( next best after the tube) than 150 W mosfet power 🤢

@@LifeIsTooShortForQRP hard choice for me then. Many say the same both are premium and probably the best Yeasu had to offer ever.

I would like to quote Al Capone on that one. "Nothing is illegal - until you get caught".

The used caps are polypropylene caps and ceramic caps. Mica is not necessary as all these replaced caps are essentially bypass capacitors.

MiniScribe M3425. It has no TI number because I replaced the original TI drive with this M3425. Problem is that a working 20MB vintage hard drive is almost impossible to find these days. I am in talks with a guy who is working on a drop-in compatible 20MB solid-state equivalent drive. That would be the only way to operate this machine with a solid-state drive, the IBM-XT solid-state drive solutions that exist for the XT won't work on this machine. So if he pulls it of, that would be the only way to operate this TIPC with a solid-state drive. I will report on this channel if he is successful.

​​@@LifeIsTooShortForQRPThat's a shame, I am a long time hard disk collector and trying to seek out those rare TI branded drives of the early 80s. I find almost all 20MB drives from this era work fine or can be repaired easily. The Miniscribe 3425, 3425+, 8425, Seagate ST-225, ST-124, ST-125, NEC D5126, D5126H, and other competitors are all very reliable options. I have about 50 ST-225s and only 7 or 8 have failed in a way that was unrecoverable. Drives of this era often get a bad name because nobody knows how to operate them or maintain them correctly. As such, I have no interest in emulation other than that it will help reduce the demand and therefore the cost of these drives when it becomes widespread in the future.

The tuner has 4 major control lines: Gnd, Key, Tune Initiate and +`12V DC. That's all you need to operate it. If the memory option is installed, 4 more lines are used: Data, Chk_Tune, Clock and Strobe. That connects to an RT100 transceiver. But these are not needed when used as a generic tuner.

I would have loved to talk to that guy. Because they used an ExOr as a phase detector in the channel synthesizer instead of a dual-D flip-flop. The former requires much more loop filtering which makes the synthesizer unnecessarily slow. You can hear that when you change channels on this rig, it takes a while for the synthesizer to lock. A Japanese rig (they always use the dual-D FF concept) is much faster for the PLL to lockup. I always believed that to be the only downside on the CPI-2000.

Download the manual www.radiomanual.info/schemi/Surplus_Civil/Raytheon_Ray-152_serv_user.pdf and go to page 6-62: CPU unit (CDC-493R) schematic diagram (fig. 6-20) At the "notes" section on page 6-62 it says ""Removing RJ2 enables the LSB transmission". Look at the manual's next page (page 6-63) which shows the position of the parts on the CPU board. RJ2 is a jumper that is located close to IC15 (MC74HC244N) on the CPU board, it is the third jumper from the left. It is marked on the board as a row of jumpers. The jumper RJ2 pulls pin 4 of IC15 normally to ground. When you remove the jumper, pin 4 of IC15 will be pulled to +5V by pull-up resistor block RA3 (8 x 10 kohm) which signals the CPU to enable the additional LSB mode. So locate the jumper RJ2 on the CPU board and remove it, this will enable LSB operation for the RAY-152 radio.

Here is one : www.ebay.com/itm/334867280044 (not my auction) You can also use a "voice flipper", then you don't have to modify the radio groups.io/g/PRC319/message/2242

@@LifeIsTooShortForQRP ok thank You. Because it is out of stock 😓

Yes, I love this radio. More than my KWM-380. I got 3 of 'em now, all mint condition TR7A's. Can't get enough of it 🙂

Lithium has a number of drawbacks. Non-rechargeables like coin cells can't deliver the current; the BC611 requires 33mA when transmitting and this is way beyond even the largest coin cells. Rechargeable Li-Ions could work, but you can't charge (or discharge) these in series without protection electronics; the voltage per Li-Ion cell is not allowed to go below 2V and not above 4.2V, that is what the protection circuitry is for. For about 30 lithium-ion batteries in series that is quite a lot of protection electronics. You could use the ones with built-in protection, but that only exists for 18650 types and 30 of those obviously won't fit in the radio. Small Li-Ion batteries with built-in protection do not exist, I have never seen those. Nevertheless, I did look into smaller rechargeable Li-ions but it is much more cumbersome to make into a larger battery. Also, those cells all come from China and I have found those to be very unreliable. I had 30% of them fail on me after only a month. If you add it all up, a home made throw-away battery from 9V alkalines is cheap and easy to make. The best way to go to get the BC-611 on the air. That was my conclusion.