SG504: Difference between revisions

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{{TM500 | mfg=Tektronix | type=SG504 | function=levelled sinewave generator | class=signal generator | image=Tek sg504 front 5.jpg | introduced=1974 | discontinued=1993 |
{{TM500 | mfg=Tektronix | type=SG504 | function=leveled sinewave generator | class=signal generator | image=Tek sg504 front 5.jpg | introduced=1974 | discontinued=1993 |
designers= |manuals=
designers= |manuals=
* [[Media:070-1632-01.pdf | Tektronix SG 504 Instruction Manual (PDF), 18MB]]
* [[Media:070-1632-01.pdf | Tektronix SG 504 Instruction Manual 070-1632-01]]
}}
}}
{{BeginSpecs}}
{{BeginSpecs}}
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compensated power meter with 50 Ω feed-thru.  See the pictures for an example.
compensated power meter with 50 Ω feed-thru.  See the pictures for an example.


As of April 2016, [http://www.ebay.com/itm/131775163056 Ebay seller "ancelb" is selling SG504 leveling (output) heads] that are specified
As of April 2016, [http://www.ebay.com/itm/131775163056 Ebay seller "ancelb" is selling SG504 leveling (output) heads]  
to perform much better than the original Tektronix heads.  See photo below.
that are specified to perform much better than the original Tektronix heads.  See photo below.


There is an open source project to replace the output head at [https://hackaday.io/project/18854-a-leveling-head-for-thetektronix-sg-504-sig-gen hackaday.io].
There is an open source project to replace the output head at [https://hackaday.io/project/18854-a-leveling-head-for-thetektronix-sg-504-sig-gen hackaday.io].


==Videos==
==Prices==
[https://www.youtube.com/watch?v=U8Gma4-jVx4 SG504 Repair and Frustraton from a stubborn unit] by Zenwizard Studios @ YouTube
{| class="wikitable sortable"
|-
! Year
! 1979
! 1980
|-
! Catalog Price
| align="right" | $2,295
| align="right" | $2,350
|-
! In 2023 Dollars
| align="right" | $9,700
| align="right" | $8,800
|}


==Service Notes==
According to an [[Media:Tek Schottky Diodes Memo rot.pdf|internal memo]], annual sales were estimated at 350 units in 1979.
*Lo Band Harmonic Distortion (Usually 3 dB or Higher) - Make sure pin diodes on R.F. Board are as close as possible to the board.
 
*Signal Output Good and Level Light is Off (at 650-695 MHz) - Suspect J39 is shorted.
==Links==
*Harmonic Distortion:
{{Documents|Link=SG504}}
**1. Make sure leads on 070 and Q120 are straight and short.
**2. Be sure C126 and C128 are centered on etched capacitors.
**3. Suspect chip caps which are heat sensitive and tend to crack.
*Reference Oscillator Out Of Specifications (50 kHz or 6 MHz) - Suspect T200 or T205.
* Adjusting for Harmonics - Excessive Harmonic levels at Low End of Low Band can be helped by adjusting C125. Adjusting C125 would lower the harmonic level but it would reduce the upper frequency on the Low Band at which time unlevelling would occur.
*Adjustment Effects - Spreading L125 decreases upper levelling frequency and decreases harmonics at low end.
**Spreading L126 has approx. equal effects - Increased harmonic level and increased upper levelling frequency. (Opposite effect of L125).
**Spreading L128 has same effect as L126 but affects upper levelling frequency more.
*Solution - Adjust C125 to set 2nd Harmonic for -26dB, compress L125, spread L126 approx. 1/16 ", spread L128 approx. 1/8". Reset C125 to begin unlevelling at first arrow past stop at upper end of dial. The worst the 2nd Harmonic should be now approx. -28dB .
**L48 should always be completely compressed.
**L45 may help harmonics by really playing with it.


==Pictures==
==Pictures==
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Tek sg504 2.jpg
Tek sg504 2.jpg
SG504.jpg |With output head (catalog picture)
SG504.jpg |With output head (catalog picture)
SG504-B013377.jpg|Late Revision Front Panel with LED Frequency Readout
Tek sw503 dc502 sg504 dc508a mr501 tm515.png|SG504 in [[TM515]] with other TM500 gear
SG504_ServiceNote_Fig1.png|Service Note Fig.1
</gallery>
'''Output Head'''
<gallery>
015-0282-00_1.jpg
015-0282-00_2.jpg
015-0282-00_3.jpg
015-0282-00_4.jpg
015-0282-00_5.jpg
015-0282-00_6.jpg
015-0282-00_7.jpg
015-0282-00_8.jpg
sg504-diy-head.JPG|Home-made output head
sg504-diy-head.JPG|Home-made output head
SG504-B013377.jpg|Late Revision Front Panel with LED Frequency Readout
Ancel sg504 head.jpg|SG504 head being produced and sold on Ebay by seller "ancelb"
Ancel sg504 head.jpg|SG504 head being produced and sold on Ebay by seller "ancelb"
Tek sw503 dc502 sg504 dc508a mr501 tm515.png|SG504 in [[TM515]] with other TM500 gear
015-0282-00_1.jpg | Output head
015-0282-00_2.jpg | Output head
015-0282-00_3.jpg | Output head
015-0282-00_4.jpg | Output head
015-0282-00_5.jpg | Output head
015-0282-00_6.jpg | Output head
015-0282-00_7.jpg | Output head
015-0282-00_8.jpg | Output head
</gallery>
</gallery>

Latest revision as of 01:25, 19 February 2024

Tektronix SG504
leveled sinewave generator
Tektronix SG504

Produced from 1974 to 1993

Manuals
(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix SG504 is a leveled sinewave generator plug-in for the TM500 system.

Key Specifications

Frequency range 50 kHz or 6 MHz (Ref), 245 MHz to 550 MHz (Lo), 495 MHz to 1050 MHz (Hi)
Output amplitude 0.5 Vp-p to at least 4 Vp-p, flat to within ±4%
Monitor output 0.3 Vp-p into 50 Ω
FM input ±9 V into 50 kΩ (DC to 100 kHz) produces ±0.05% to ±0.4% deviation depending on frequency

Output Head

The SG504 is usually found on Ebay without the output head (015-0282-00). David Partridge did an excellent teardown and reverse engineering of the output head and sells kits to make new heads.

It's fairly easy to use that schematic to make a new level head that fits in a standard BNC Pomona box since its function is really just a 250 MHz to 1050 MHz temperature compensated power meter with 50 Ω feed-thru. See the pictures for an example.

As of April 2016, Ebay seller "ancelb" is selling SG504 leveling (output) heads that are specified to perform much better than the original Tektronix heads. See photo below.

There is an open source project to replace the output head at hackaday.io.

Prices

Year 1979 1980
Catalog Price $2,295 $2,350
In 2023 Dollars $9,700 $8,800

According to an internal memo, annual sales were estimated at 350 units in 1979.

Links

Documents Referencing SG504

Document Class Title Authors Year Links
070-2088-01.pdf Book TM500 Series Rear Interface Data Book 1976
Tekscope 1976 V8 N1.pdf Article New Products 1976
070-2088-04.pdf Book TM500 Series Rear Interface Data Book 1985

Pictures

Output Head