... You are assuming that the adustment is the only problem. A fix may no be possible with just the adjustment. I suggest working out details off list, but be...
FOR SALE: Interface modern transceivers with older tube linear amplifiers with ease with this plug-and-play device. Manufactured by Mike, WB8VGE of SunLight...
http://cgi.ebay.com/Early-Heathkit-H-8-Computer-Programming-Manuals-/380294653648?pt=LH_DefaultDomain_0&hash=item588b53e6d0 380294653648 Just a heads up, not...
Hello everyone, I've noticed that my HW-101 has full output on every band except 40m and the symptom that occurs is that it gives full output power above about...
You're welcome. Visio is a good drawing program, and I "print" to PDF so everyone can have it. Just now, I modified the SB-620 file to work for the SB-610 and...
I suspect you are right, 40 meters is quite possibly not aligned properly. If you have the 101 manual then turn to the alignment section and follow the steps...
Two other additions to the discussion.....The clear material I used to back-up the transparency is K&S Plastic, stock # 1306, .030 in thick. I'm pretty sure I...
Hi Everyone: I have a query for the group. I have a IM-18 VTVM and really would like to begin using it again. My question is on the probes. I, of course,...
... Hi Carey It is not a modification I would recommend unless you have the specific need to make measurements with neither of the probes grounded. I seem to...
You cannot use normal VOM probes. The VTVM has a 10M resistor in it. But you can make your own probe. The information is in the VTVM manuals. Bob Macklin K5MYJ...
I don't recommend those modifications either. Use a VOM if you need to use a meter that is floating. Get a Heath VTVM manual and make a new probe. The resistor...
This is a bad idea. The resistor is in the probe for a reason. If all else fails, cut a regular probe wire as close to the end as you can, solder in a 1 M...
1 meg., not 10. Neil From: Bob Macklin You cannot use normal VOM probes. The VTVM has a 10M resistor in it. But you can make your own probe. The information is...
Sorry about that! You are correct. 10M is the value in scope probes! I have done it with a normal VOM probe set. Bob Macklin K5MYJ Seattle, Wa. "Real Radios...
The reason for the isolating resistor is pretty well covered in the following book extract.* * Regards, Brian* * *Isolating Probes* /(Extract from the book...
Hi, Carey I can sell you a Triplett VTVM probe, which includes the switched resistor feature, new old stock for $18 shipped. It's a very good quality shielded...
18626
Mike McCarty
Mike.McCarty@...
Dec 3, 2010 2:17 am
... [...] ... I have a need for "several". How many do you have? Mike -- p="p=%c%s%c;main(){printf(p,34,p,34);}";main(){printf(p,34,p,34);} Oppose...
Cary, Hope this helps. Pls see attached. Probe Schematic is on left. Joe KJ4YJL All that is necessary for the triumph of evil, is for good men to do nothing. -...
18628
Mike McCarty
Mike.McCarty@...
Dec 3, 2010 2:30 am
... Difficult. ... There are two good reasons not to do that. First, that resistor isolates the circuit under test from the probe capacitance. Second, it also...
18629
Mike McCarty
Mike.McCarty@...
Dec 3, 2010 2:30 am
... If you sent this to the group w/attachment, then know that it got stripped. If you sent it also under separate cover to Carey, then he got it there. Mike ...
I have an AJ15 question. This tuner has been in my shop now for the last 15 years. I have it with an AA15 ... a perfect pair so's to speak.Works perfectly as...
18631
Mike McCarty
Mike.McCarty@...
Dec 3, 2010 3:03 am
Steve Vormbrock wrote: [...] ... My nose tells me it may be a component which has become temperature sensitive, likely a capacitor. I suggest getting out a...
... Focus on the area of Q405, Q410, and Q411. Check resistor values for drift. Replace with film types where needed. Also, C416 should be a tantalum type...
Actually, the mod makes perfect sense for anyone that doesn't have the original probe, plus it simplifies the day to day use of the VTVM. It does have a...
If you want to use a VTVM from this period you should use it as designed. I think this is an RCA original design. All VTVMs of this period were built this way....
18635
Mike McCarty
Mike.McCarty@...
Dec 3, 2010 6:09 pm
... It does not make any sense whatsoever, since the adjustment range of the calibration pot is adequate to calibrate the DC ranges to be accurate w/o the...
Gee, Kinda makes one wonder why Heath's engineers went to all the trouble, AND COST, to design and include that switching probe for ALL their VTVMs. Just...
Folks: Many thanks for all of the replies and discussion both on the reflector and off. Great bunch of very helpful folks. I appreciate the bandwidth. My...
... Not to mention TV sets of the era were rife with all sorts of RF/magnetic fields, and draping an unshielded lead around/across a chassis to get to some...
