Call Search

New to Ham Radio?
My Profile

Friends Remembered
Survey Question

DX Cluster Spots

Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement

donate to eham
   Home   Help Search  
Pages: Prev 1 2 [3] 4 5 6 7 8 ... 10 Next
 on: Yesterday at 08:06:14 PM 
Started by KI4EU - Last post by KI4EU
I was able to take the pot apart and clean and repair it.  Working fine now.

 on: Yesterday at 08:04:53 PM 
Started by W9BB - Last post by KA5IPF
That is a "Service" menu, there are no defaults and you can't compare rigs because each is unique. I have never seen 2 with the same numbers, just like I've never seen two that would align the same due to variances in parts. You didn't say what the power out on the other two was actually (measured) but I guarantee it is well over 100w meaning someone has been in there diddling. The power meter has to be aligned after several other steps including setting the power correctly in 18. If the proper procedures are not followed the power meter will show 100w no matter what the actual power is.

It is not a simple as going to Menu 18 and cranking away.

 on: Yesterday at 08:00:07 PM 
Started by N6QWP - Last post by VK6HP
Frank, I would not tie myself in knots over this.  As I mentioned in the previous posts, it's not that critical and extraneous factors - like line voltage and tube brand/condition - all enter into the final choice.  My own approach would be to try what values you have on hand and check the standing current.  If it's in the region of 100-110 mA, leave well enough alone.  I note that your amp came to you with 40 ohms (nominal) for R28, so perhaps start with 39 ohms and see where it takes you. Do you recall if the quiescent current looked OK prior to your "event" ?

I'm interested in Jim's references just for completeness of my files.

PS: just noted your previous post, which crossed with mine.   My manual is a 9th edition, 1 Feb 1968 and has R28=39 ohm, as I mentioned.

 on: Yesterday at 07:58:23 PM 
Started by N6QWP - Last post by N6QWP

The 8th edition of the 30L-1 is dated 7-15-66.  The schematic shows the value of R28 to be 39 ohms.

The addendum included with it in the archives is dated 1-9-61=OUTDATED AND MISFILED!!!

So Jim, I think that this explains the discrepancy of your advice on the value of the R28 update to lower the temp of tubes and amp.  Not your fault.

UNLESS I AM WRONG?,  the value of R28 should be changed to 39 ohms +/-, along with the other suggested replacement values......if not already done so.

the updates in The Care and Feeding of Your 30L-1 article are valid.

This has been a very informative endeavor to research and get right the proper updates for me.  I hope that all of those who have followed along have also learned from this thread.

Thanx to all that have helped.  I will proceed to install the parts and troubleshoot the rest of the amp.  Will come back when done to advise of the success of my efforts.....or not?  Wish me luck in my hopes that the problem has not gone all the way to the transformer winding.  I already purchased another relay, in case it was hit in the flashover.  73 all.

 on: Yesterday at 07:54:30 PM 
Started by K7QA - Last post by K4SAV

There is no reason to not experiment with different receiving antennas.  I have done that too, for many years.  You can learn a lot by taking good experimental data if you have a reference to compare the antennas against. 

Usually a NEC analysis will tell me what I need to know about an antenna, but there are exceptions.  I don't think either NEC2 or NEC4 calculate the pattern for a BOG correctly.  That's the reason I built two of different lengths, pointed them in the same direction, and spent a whole month taking data to determine their characteristics.

NEC gave me an answer for those two antennas after about 15 minutes, but later I measured the current on a BOG and found that NEC wasn't even in the ballpark at predicting those currents.  If the currents are wrong, so will be the pattern.

Something else often overlooked when doing a NEC analysis is the common mode current problem.  Most people don't include the contributors in their models.  Single element antennas like K9AY, EWE, flag, pennant, delta, diamond, etc will all have about the same RDF but some are more sensitive to common mode than others, and some are easier to build than others.

Jerry, K4SAV

 on: Yesterday at 07:46:05 PM 
Started by KM5PS - Last post by K9AQ
I run 75 ohm CATV hardline from my shack to my tower.  I build two 75 to 50 ohm transformers.  I am out of town and don't have access to the information on how I build them.  I used a design from Jerry Savick's book.  I will send more information when I get back home.


 on: Yesterday at 07:31:42 PM 
Started by K1YTG - Last post by WB2NGX
1.1 to 1.25 isn't much of a change, temp and humidity can do that.


 on: Yesterday at 07:25:16 PM 
Started by W4OEQ - Last post by KC0W
 Been playing with FT8 on a K3 & a FT-857. Both rigs will stop immediately when Stop or Halt is pushed.

                                                             Tom KC0W

 on: Yesterday at 07:24:06 PM 
Started by W6TGE - Last post by VA3VF
Bill, can you go over some of these upgrades, and can you tell us when they will go public?

No timeline has been announced for the next public release, but tweaks and adjustments are made almost daily. A change made today may be removed tomorrow. Nothing is final until the public release.

The revisions are still called 1.7 dev, but they are actually 1.8 RC2 plus.

 on: Yesterday at 07:14:30 PM 
Started by KE7XD - Last post by W9IQ
Antenna gain does not change but gound reflection and lobe angle does.

Near field ground reflections (and losses) are part of the antenna gain.

- Glenn W9IQ

Pages: Prev 1 2 [3] 4 5 6 7 8 ... 10 Next
Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!