Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 22nd June 2008, 11:36 PM   #1
diyAudio Member
 
Zero Cool's Avatar
 
Join Date: Sep 2004
Location: MN
Default Hickok Upgrades

I recently purchased a Hickok 533A as i am getting more and more into tube amplifier repair and building.

I am about to send my unit off to be calibrated and check out and have anything that needs to be repaired, repaired!

The case for my 533A is in rough shape. My father who is retired now enjoys woodworking is going to build a new case for it. But before i give him the final dimensions i am considering some additions and upgrades and wanted to start a thread to talk about several of them and maybe see what others have done.

One website shows a new panel mounted in the upper cord carry slot with a removable power cord and the addition of 3 digital meters. one for Line Set. one for Grid voltage and one for plate current. other testers show other options like test points for every pin, binding post's for insertion of a ammeter for plate current. etc.

I am thinking about doing the same sort of thing in the new case with an upper panel added with a digital line set meter. Probably a 3-1/2 digit meter, but if i can find a 4-1/2 digit i might go with that for the increased accuracy.

I am also thinking about matching digital meters for Grid-V and Plate current but thought of going one step father and adding a digital filament voltage meter as well to check for transformer sag. and two steps further to add test points for all pins, Line V, Grid V, Filament V, and post's with a removable jumper for Plate current. This should allow me to roughly match tubes as well.

I wonder if i could add dual Plate Current and Grid Voltage meters to check both sections of a triode at the same time with the 533A??? Internally it only test's one section at a time so i don't think i can without major modifications. But one section at a time should be good enough.

I am considering changing out the 83 and 5Y3 tubes for solid state rectifiers for increased accuracy and reliability. There is some debate over if this should be done as i have found from website to website. Issues with increased voltage etc are problematic if the Solid state replacements don't take this into account. One eBay seller's adds even clearly shows the differences in readings right on his ad! I don't think he understands WHY the readings are different.

I am interested in discussing the SSR option if others have done it and have experiences good or bad with them.

Does anyone know of a source for replacement roll charts? I wonder how much interest there would be if i could have new charts made?? I have access to a large format inkjet plotter at work and i could easily make new charts if there was demand.

Looking at the schematic of this unit i see that they use a 200 ohm 20 watt rheostat in series with the transformer primary to set line voltage. would there be any advantage to changing that to a small variac? I have seen some small 2-3 amp units that would fit in place.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Anyone Have a Hickok 800A skidave Tubes / Valves 6 22nd December 2008 02:30 PM
Hickok 800 settings darryljoe Tubes / Valves 2 21st June 2007 04:42 PM
Hickok 536 meter slyoldfoxx Swap Meet 0 4th May 2004 05:24 PM
What is a Hickok 533 worth? G Tubes / Valves 3 9th December 2003 05:30 AM
Hickok 600/605/800 settings? lgo51 Tubes / Valves 1 3rd May 2002 03:18 AM


New To Site? Need Help?

All times are GMT. The time now is 09:42 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2