Jay--- Take warning---
The TEK 491 SA has a very primitive front end mixer in it. This mixer is not a balanced type and passes considerable input signal direct to the IF amplifier which is in the 150 to 250 mHz region, if I remember right. This mixer blow through makes for considerable confusion in off air measurements and actually in most VHF applications------it is fine up in UHF and microwave. We have one here that was given to us-----we have plans to replace the mixer with a Mini Circuits balanced type with hopes for improved to usable performance. Scott, N6NXI ----- Original Message ----- From: Jay Sario To: [email protected] Sent: Thursday, July 26, 2007 7:30 PM Subject: [Repeater-Builder] Tektronix TEK-491 spectrum analyzer Hi to everyone, A fellow here in our location is selling me a cheap working Tektronix 491 spectrum analyzer that doesnt have the standard accessories. My knowledge on how to use this type of equipment is limited at the moment but very interested in getting to know how. Just would like to ask before I buy it, would I still be able to put it in good use or be able to measure things even if the standard accessories are not included, like the waveguide mixers, etc.? Can i substitute them with homebrewed ones? Thank you much. jay
