I have had the problem and turned out to be the antenna relay. I think the power supply, CR 102 failed, causing the hum. Activate the antenna relay and see...
Robert Montgomery
RMonty3@...
Aug 1, 1998 12:35 pm
1880
I would like to purchase an original CV-157 Tech manual in good condition. Pse Email or phone ramsta@... or 619-659-1215 ...
RAMSTA
ramsta@...
Aug 1, 1998 10:26 pm
1881
Thanks Monty, Mr. Rovero made a similar suggestion. Others seem to feel that xfmr cores cannot vibrate; they could make big bux building F1 chassis. 73, ... ...
Steve Stutman
sstut@...
Aug 1, 1998 11:03 pm
1882
I have a very nice R-390A that I don't want to sell but I need to so I can pay bills. This R-390A is made by Stewart-Warner contract 20139-PC-60 serial # 2756 ...
KB0UPL@...
Aug 2, 1998 12:01 am
1883
... I think its the PSU area, but the later suggestion on CR102 failure is worth getting it out of the rack to check out......Ill do it next week Pete ... ...
Peter Worrall
worrallp@...
Aug 2, 1998 1:15 am
1884
Transformer cores can and DO vibrate. Its from magneto striction if nothing else where the magnetic field causes the iron to change size slightly. The closer...
Dr. Gerald N. Johnson...
geraldj@...
Aug 2, 1998 1:53 am
1885
Hi, Thanks to all who commented on the hum. I stand corrected; Jerry is correct as to 120 cyc from cores. If I were a little more musical perhaps I could...
Steve Stutman
sstut@...
Aug 2, 1998 2:43 am
1886
Copper oxide had a fair drop when new and now it could easily be 15 volts with back leakage only a few times forward resistance. Copper oxide rectifiers were...
Dr. Gerald N. Johnson...
geraldj@...
Aug 2, 1998 2:51 am
1887
OK -- next week is the 'clean up and see what needs replacing' exercise on the new 390A -- two questions: 1) I seem to recall there is a capacitor in the IF...
Kenneth Vito Zichi
aa024@...
Aug 2, 1998 3:07 am
1888
Just a brief warning from an experience I had last weekend . I turned on my 67 EAC 390A after it had sat unused for at least 6 mo. and heard an erratic...
Jim Carrington
jcall@...
Aug 2, 1998 6:49 am
1889
Gang .. I've acquired a TMC CV-591A to use with my R-390A for SSB reception. Been through and replaced the non-ceramic caps. Almost all the resistors are a...
Grant Youngman
nq5t@...
Aug 3, 1998 2:47 am
1890
I run my 390 on standard UK ac mains. This is 230 volt 50 Hz nominal, but in my case, its up to 240 most of the time. The hum I experience seems to come...
Peter Worrall
worrallp@...
Aug 3, 1998 9:07 am
1891
Message-ID: <35C5BF9B.7D72@...> Date: Mon, 03 Aug 1998 08:48:30 -0500 From: "Dr. Gerald N. Johnson, P.E." <geraldj@...> Reply-To: geraldj@... ...
Dr. Gerald N. Johnson...
geraldj@...
Aug 3, 1998 3:19 pm
1892
Hi, Seems to me that flux is flux. Whether you have two primary windings in series or parallel, amplitude of noise should be same, xcept for second order...
Steve Stutman
sstut@...
Aug 3, 1998 5:10 pm
1893
Steve, 50 hz vs 60 hz is NOT a secondary effect on flux. The flux density in a particular core with a fixed number of turns is directly proportional to voltage...
Dr. Gerald N. Johnson...
geraldj@...
Aug 3, 1998 7:37 pm
1894
OK Jerry; A+, nice analysis. But,all I meant was that intuitively I didn't think power xfmr on a COLLINS designed radio would be close to the edge. We...
Steve Stutman
sstut@...
Aug 3, 1998 8:27 pm
1895
Just a quick R390 story for the group. I picked up a very clean R390 at a ham fest a few weeks ago. I've been enjoying rebuilding my R390A (and learning about...
Gary Kaufman
gkaufman@...
Aug 3, 1998 8:36 pm
1896
I realize that these are as scarce as hen's teeth, but would anyone any of these R390 parts? tube pullers or tools from back panel RF or crystal covers Many...
Gary Kaufman
gkaufman@...
Aug 3, 1998 9:02 pm
1897
The radio I believe is specified from 50 to 60 hz. I don't think Collins specified the transformer details enough to control how conservative the windings are....
Dr. Gerald N. Johnson...
geraldj@...
Aug 4, 1998 12:07 am
1898
Hi Pete, ... I run mine on Aussie mains which is more often low than high and I have the same hum although I must confess it doesn't really bother me. It's ...
Morris Odell
morriso@...
Aug 4, 1998 12:07 am
1899
Agreed. I've found that a few toroidal mains xfmrs; one homebrew, a couple in audio gear, sing a lot when on same circuit as triac. Presume that they are...
Steve Stutman
sstut@...
Aug 4, 1998 2:18 am
1900
I would like to get the original black meters in exc working condition. Tks, Mike/KC8CU/San Diego ramsta@... or 619-659-1215 ... ...
RAMSTA
ramsta@...
Aug 4, 1998 2:54 am
1901
Hi Mike, I think I can fix you up with some meters. I have two sets of black meters. You can have your pick. $55 for the set. Ben -- WB8HUR San Diego ... ...
Ben Wallace
bwallace@...
Aug 4, 1998 3:29 am
1902
Hi I am thinking about remanufacturing the top and bottom covers for the R-390A they will be just like the Original. Any intrest? Mort W6KLG ... Submissions...
Morton Jones
mortjonz@...
Aug 4, 1998 4:55 am
1903
Tittle says it. I need that Trim Cap Cover that is on the back of an R-390 (NOT A - as it doesn't have one there!) TIA, Walt... Wally's Wacky World ...
Walter Quitt
wa6fec@...
Aug 4, 1998 5:14 am
1904
... I got mine from Rick Mish at Miltronix in Toledo, Ohio. He has them in stock. Rick can be contacted at: Phone or Fax: (419) 255-6220 U. S. Mail: Rick...
James D. Howard
jdhoward@...
Aug 4, 1998 10:23 am
1905
Hello all r390 fans For those of you who like to use your r390a/urr for usb there is two stations to check it out that are on 7/24 freqs are 4278.5 and...
clarence
clarence@...
Aug 4, 1998 2:23 pm
1906
Hi, I'd like to find an original manual-not reprint or photocopy- for the R-390/URR. The TM 11-5820-357-35 is the depot maintenance manual and is the one I'm...
Chip Owens
owens@...
Aug 4, 1998 4:36 pm
1907
RE>>[R-390] USB testing 98 08 04 Well...I've been monitoring them since reported and I have been surprised that they have been up this...
Richard McClung
richard_mcclung@...
Aug 4, 1998 11:32 pm
1908
Yes they do go off, but they are usually back up shortly they are up now 2000utc with a big signal. Best Regards clarence@... Eastern,Texas ... From:...
