HP 8904A Unit 2 Restoration and Check in

Рет қаралды 2,281

Ай бұрын

A huge thank you again for all that continue to Join us in the lab for repairs and alignments. The channel would not exist with out all of you so thank you again for dropping by.
Ways to support the channel:
Patreon - / zenwizard_studios
Paypal - Zenwizard@Zenwizardstudios.com
In this video we take a look at another HP 8904A Synthesized function generator. I have been looking to grab a few of these for the lab to assist with alignment and calibration of FM tuners. This was also an incredibly stable function generator for the time and still to this day. With some of the built in modulation abilities it will be a welcome addition to the bench….. Once we fix the display issues.
** Repair exposes the Tech to mains electric and should only be done by trained personnel. Errors can be fatal. **

Пікірлер: 6

@darrenmurphy6251 Ай бұрын

dont know what the kit is for but interesting anyway best guess ,is it a dds sig gen thats sync-able with a time base reference? in the uk we dont get access to hp gear

@ZenwizardStudios Ай бұрын

It is a low speed function generator DC - 600 Khz. There was an option that was allows for phase lock of up to 8 units. I needed 2 but the units I have do not have the Sync inputs on the back OP5 if I remember correctly. So I will need to find another way of getting phase locked outputs.

@darrenmurphy6251 Ай бұрын

@@ZenwizardStudios ok phase locked wow thats cool serious tech oh and didnt know about sheiffer emi filter blocks so thanks ,seen loads of cracked rifa,s though but never an incinerated one ,i had a vega tv (russian) filter cap class x across 240v blow up in my face and seriously no bull iam convinced it was brown parcel tape just without the glue! that was back in the 90,s unrelated tech question : the yellow arrow shaped axial tantalum caps in 80s- 22 and 24 series tek scopes what do you replace them with when they cook the pcb , are low esr electros good enough now or are the tantrums better esr than that?

@ZenwizardStudios Ай бұрын

that really depends on the circuit and service. If the tants are just decoupling caps for the power rails then low ESR electrolytic are fine, Usually.

@stephenbell9257 Ай бұрын

@@darrenmurphy6251 The brand of the bad mains input filters is Schaffner not Sheiffer. Check the date code on any of these filters you come across and immediately replace anything dated prior to 2000. Later years started using some better quality caps that weren't quite so prone to exploding.

@darrenmurphy6251 Ай бұрын

@@stephenbell9257 ive got loads of gear 80s to 90s, 22xx and 24xx tek scopes fluke 8840,s solartron ect , so time to get busy