[R-390] PTO

Sat Sep 4 00:11:30 EDT 2010

As a reality check, you might consider injecting a signal more 
towards the back end of the receiver.  Insert the hot lead of the sig 
gen output down in between a selected stage's tube and its 
shield.  Use a wire with high temp insulation like teflon. Be careful 
not to let the end of the wire touch any of the tube pins.  Some tape 
or heat shrink on the wire end would help here.

Likewise, to use your DX390 to sniff oscillator frequencies, connect 
a suitable length of coax and expose a stub of the insulated center 
conductor at the far end.  Again, use tape or heat shrink on the very 
end.  With this you should be able to sniff oscillator signals 
without overloading the DX390.  If you need more attenuation, try 
adding additional shunt C or shunt R at the input of the DX390.

Regards,
Jon, WA3MVM

At 09:41 PM 9/3/2010 -0500, ka9egw at britewerkz.com wrote:
>I just had the rf deck out again, and the rf bandswitch is right, crystal
>switch is spot-on, cam positioning is right at 7+000.
>
>I'm planning when/if I go back to it to start looking for a failure
>elsewhere in the system.
>
>73 de ka9egw
>
>-----Original Message-----
>From: r-390-bounces at mailman.qth.net
>[mailto:r-390-bounces at mailman.qth.net]On Behalf Of ka9egw at britewerkz.com
>Sent: Friday, September 03, 2010 9:11 PM
>To: Craig C Heaton; r-390 at mailman.qth.net
>Subject: Re: [R-390] PTO
>
>
>Nah, the only thing it can hear is my sig/gen at an absurd input level, at
>7.035 and 8.035 [seemingly verifying what visual inspection told me when I
>reassembled the RF deck...although that jibes with the display
>indications...and some spurs at indicated 0+000 and 1+000 and a birdie at
>910.  I haven't looked higher than that.
>
>The cam alignment at 7+000 is spot-on, the rf bandswitch rolls over between
>7 +000 & 8 +000 just like in the tutorial, and 7+000 equates to the 7
>showing in the window on the crystal oscillator deck, and visual inspection
>before reinstalling the rf deck/crystal deck assembly confirmed the contacts
>were right in line.
>
>Is it somehow possible to have the crystal oscillator bandswitch mis-indexed
>to the indicator drum inside the crystal deck, without having done anything
>to the crystal deck on a previously-working receiver?
>
>By the way, I'm using a known-good, plug-and-play IF deck just received from
>Fair Radio.  The known-good PnP RF deck should be here Tuesday.
>
>Or could I have the MHz side of the...I dunno.  I need to walk away from it
>for a few hours.  I'll be yanking the blankety-blank
>rf deck again tomorrow.
>
>73 de KA9EGW
>
>-----Original Message-----
>From: Craig C Heaton [mailto:wd8kdg at att.net]
>Sent: Friday, September 03, 2010 8:22 PM
>To: ka9egw at britewerkz.com; r-390 at mailman.qth.net
>Subject: RE: [R-390] PTO
>
>
>Looking back, I think this is still about an "A". So if it is get a copy of
>the Y2K, print the beast and follow along.
>
>The mechanical alignment has to be done first, check cam position at 7 +000,
>etc. If the receiver can hear signals, set it for one of WWV's TX's; 5 10 15
>or 20 MHz. Loosen a clamp on the PTO, keep the veeder root, cams, etc from
>moving, turn PTO shaft only until WWV is zero beat. (BFO on)
>
>This should get you in the ball park.
>
>Craig,
>
>-----Original Message-----
>From: r-390-bounces at mailman.qth.net [mailto:r-390-bounces at mailman.qth.net]
>On Behalf Of ka9egw at britewerkz.com
>Sent: Friday, September 03, 2010 5:37 PM
>To: r-390 at mailman.qth.net
>Subject: [R-390] PTO
>
>The saga continues...it goes without saying the rf deck is now horribly out
>of alignment.  I can get the rx to hear my sig/gen on the antenna input, but
>that's about it.
>
>Lacking access to a freq counter, but having a decent sandstate general
>coverage rx, [a Rat Shack DX390 which is possibly too sensitive for this
>use] how do I go about telling where the pto is really at?  I've got more
>than my share of intermod and spurious mixing products and can blank the
>receiver 50 times when tuned through 10 turns starting at the
>counterclocksise.  [When I say 'stop' I mean that point where the resistance
>of the bare pto shaft to my bare fingers just starts to increase marginally,
>I am being very careful not to run the pto past it's physical limits...]
>
>Assuming I'm at the full CCW stop on the pto, where should it be?  It's a
>Collins PTO FWIW.
>
>I won't even go into my planned 'someday' change to the Cosmos I have on teh
>shelf...
>
>Any help would be appreciated.
>
>73 de KA9EGW
>
>______________________________________________________________
>R-390 mailing list
>Home: http://mailman.qth.net/mailman/listinfo/r-390
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:R-390 at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html
>
>No virus found in this incoming message.
>Checked by AVG - www.avg.com
>Version: 9.0.851 / Virus Database: 271.1.1/3112 - Release Date: 09/03/10
>13:34:00
>
>______________________________________________________________
>R-390 mailing list
>Home: http://mailman.qth.net/mailman/listinfo/r-390
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:R-390 at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html
>No virus found in this incoming message.
>Checked by AVG - www.avg.com
>Version: 9.0.851 / Virus Database: 271.1.1/3112 - Release Date: 09/03/10
>13:34:00
>
>______________________________________________________________
>R-390 mailing list
>Home: http://mailman.qth.net/mailman/listinfo/r-390
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:R-390 at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html