Thanks to all who replied. At this time, the rig is working for unknown reasons. I guess it is going to be a PITA intermittent.
I so often see a problem on the list and then see thanks but never the answer as to what fixed the issue. For those looking in the archives for answers, it is a disappointment. I too went "off list" with some e-mail, info is reposting below. ==== Ron WD8SBB: ...Although the rig is playing now, it twice showed issues similar to that described below (check 5, 7, + 21Mhz freq).....I have tried to poke apart T2101 with a plastic stick, but it appears fine.... =============== ==== Gary, W8PU: Ron, It looks as if the wrong bcd code is going to the translater board causing either the VCO to hunt ( out of range ) or for the wrong frequency to be generated for a given bandswitch position. Try reseating the DR-7 board. 73, Gary ================ ==== Garey K4oah: Interesting..... I've never heard of a solid state power supply needing a "warm-up"! :-) I would be suspicious of C2109 or C2108 also, although usually leaky caps go the other way, i.e., leakage goes UP as they warm up. The diodes in the bridge are switching diodes, but should work ok. I'd look at C2108 and C2109 at turn-on to see if they ramp up. I've never looked, and it's possible that this is NORMAL, since it comes up fairly quickly. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs <www.k4oah.com> ================ --- On Sat, 1/30/10, Ron <[email protected]> wrote: > From: Ron <[email protected]> > Subject: Re: [Drakelist] TR7 acting strange > To: [email protected] > Cc: [email protected] > Date: Saturday, January 30, 2010, 12:16 PM > Garey, > Even thought I had spontaneous healing of my TR7 per our > e-mail discussion, I opened up the rig and did some voltage > tests. Rig in SSB, all boards installed. > > Pin spec measured > 1 -5V -3.43 > 2 +25 23.3 > 3 gnd > 4 AM 4.99 > 5 RTTY 7.01 > 6 CW 4.31 > 7 LSB 6.26 > 8 USB 3.83 > 9 DCin 13.53 > 10 +10VDC 10.01 > 11 +5V 4.90 > > The 24VDC line stayed solid as I moved the bandswitch and > up down buttons. > > Per the drake service dept alignment procedures, pin 2 > should measure between 23.25-24.0. Assuming my meter > is accurate, that voltage is very close to being out of spec > low. Maybe a weak/leaky C2110? > > I could not get to the input of U2103 (24V regulator) > without pulling the DR7 board. Pulled it and installed > probes and then reinstalled the DR7. Input to the > 78c24 was at 27VDC immediately after turning on the rig, and > then climbed to 32-35 volts w/i about 10 seconds. As I > recall the 7800 family of chips need 2 volts to regulate, so > I think input is w/i spec even at turn on. When > switching the bandswitch, it made the input voltage move, > but never under the 32 volt level. Caveat, using a DVM > so it may have "spikes" that I was not seeing. > > After this, I pulled the DR7 and replaced it with the > service kit "jumper logic board". Basically had the > same results with it in place of the DR7 board. > > TNX es 73, > Ron > > --- On Mon, 1/25/10, Garey Barrell <[email protected]> > wrote: > > > From: Garey Barrell <[email protected]> > > Subject: Re: [Drakelist] TR7 acting strange > > To: "Ron" <[email protected]> > > Date: Monday, January 25, 2010, 9:56 AM > > Ron - > > > > Definitely sounds like marginal VCO locking. > > > > The bands from 160 - 20M will all wander around 17 > > MHz. 15 and 10M > > bands will wander around 34 MHz. > > > > An "open" AUX-7 position will result in an unlocked > VCO, as > > will pushing > > the FIXED RCV button in. > > > > First step is to check that +24V DC supply bus. > That > > is the most likely > > cause of this, i.e., "random, occasional, loss of > lock" on > > both PTOs. > > Certainly there are other possible causes, but that > little > > transformer > > core is a problem, and the "super glue" that Drake > used to > > put it > > together is letting go (after only 40 years or so). > > Easy fix, just glue > > it back on. > > > > 73, Garey - K4OAH > > Glen Allen, VA > > > > Drake 2-B, 4-B, C-Line& TR-4/C Service > Supplement > > CDs > > <www.k4oah.com> > > > > > > Ron wrote: > > > Garey, > > > I started to look at the TR7 last night. First > > was to see for sure what was going on frequency > wise. > > Turned it on, 80 meters, where I had left it and it > was > > fine. 2.5 then 1.5 wondering 17xxx.x 1.5. Back > > to 80 meters fine, and of course everything else was > fine > > too. So then I went back down to 2.5 and 1.5, they > too > > were fine now. So I thought maybe temperature or > time. > > Could not get it to fail after several hours. > > > > > > Got to playing and went to aux settings. They > > were fine with the band light lighting if I was not in > the > > correct band. Then I went to an open aux location > and > > got wondering 17xxx.x. I can not remember it that > has > > always been that way or not. Looks like it could be > > correct given the "block" diagram of the rig in my > head. > > > > > > So I know it sounds like VCO/PLL issues, which > > voltages are most likely. But, is there anything in > > the bandswitch that exercise might cause to "clean > > up"? Or am I in for what looks to be a PITA > > intermittent? > > > > > > Also, I have looked for how my TX is open. The > > motherboard out of lock trace is not cut, and the > Q9001 > > collector on the DR7 board seems in tack. Maybe I > just > > missed how they defeated Q9001. Is there something > > with the aux board that also somehow "opened" the TX? > I > > thought it was only for the modules in aux, not the > whole > > TX? > > > > > > Thanks in advance. Also thanks for being an > anchor for > > this list. Your knowledge and willingness to share > that > > knowledge is a tribute to the real meaning of Ham > Radio. > > > > > > 73, > > > Ron WD8SBB > > > > > > --- On Sun, 1/24/10, Garey Barrell<[email protected]> > > wrote: > > > > > > > > >> From: Garey Barrell<[email protected]> > > >> Subject: Re: [Drakelist] TR7 acting strange > > >> To: "Ron"<[email protected]> > > >> Cc: [email protected] > > >> Date: Sunday, January 24, 2010, 4:40 PM > > >> Ron - > > >> > > >> You may need to recheck your frequencies. > > ~17 MHz is > > >> the "target" frequency for the Lo Band VCO > > (through 20M), > > >> and 34 MHz for 15 and 10. This is where > the > > VCO's > > >> settle when unlocked. > > >> > > >> First thing to check is the +24V DC > supply. > > This > > >> higher voltage is used for the Loop Filter > and > > VCO > > >> steering. If the voltage is low, check > that > > "E" core > > >> on the DC/DC converter transformer on the > little > > power > > >> supply board. > > >> > > >> There are other possibilities, but this is a > > start. > > >> Unless the transmitter has been modified, it > won't > > transmit > > >> if the VCO is unlocked. > > >> > > >> 73, Garey - K4OAH > > >> Glen Allen, VA > > >> > > >> Drake 2-B, 4-B, > > C-Line& TR-4/C Service Supplement > > >> CDs > > >> <www.k4oah.com> > > >> > > >> > > >> Ron wrote: > > >> > > >>> Got a strange one going on. Finished > and > > 80 > > >>> > > >> meter net and was headed to 40 to listen to > the > > Drake tech > > >> net. On 80 meters it work find. But > > when I go to > > >> other bands, the display shows incorrect > > frequencies. > > >> Also on using the up/down buttons it will go > into > > strange > > >> frequencies as well. > > >> > > >>> 1.5 show 1759x.4 and counts up slowly > > >>> 2.5 same as above > > >>> 3.5 80 meters okay and transmits > > >>> 5 shows 1414.x > > >>> 7 shows 3415.x14 displays okay > > >>> 21 shows 17415.x > > >>> 28 ok > > >>> > > >>> I did not go further and attempt to TX > for > > fear of > > >>> > > >> further injury. > > >> > > >>> It would appear the VCO/PLL are messed > up, but > > why > > >>> > > >> such strange combinations? > > >> > > >>> First thing will be board removal and > > reseating unless > > >>> > > >> someone has a specific I should be looking > for. > > >> > > >>> TNX es 73, > > >>> Ron WD8SBB > > >>> > > > > > > > _______________________________________________ > Drakelist mailing list > [email protected] > http://mailman.zerobeat.net/mailman/listinfo/drakelist > _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
