Phantom 70MHz Variable BW filters on Ebay

[s-band]

These must be extremely rare now. They weren't that common way back. If anyone still has an analogue RX with 70MHz loop these are a must-have accessory @John

Phantom Adjustable Bandpass Filter tuned to 70 MHz New In Boxed NOS | eBay

<p>Phantom Adjustable Bandpass Filter tuned to 70 MHz New In Boxed NOS. </p><p>New old stock</p><p>Model 70</p><p>Serial 31370</p>

www.ebay.co.uk

Pics saved for posterity

 

[John]

These must be extremely rare now. They weren't that common way back. If anyone still has an analogue RX with 70MHz loop these are a must-have accessory @John

Phantom Adjustable Bandpass Filter tuned to 70 MHz New In Boxed NOS | eBay

<p>Phantom Adjustable Bandpass Filter tuned to 70 MHz New In Boxed NOS. </p><p>New old stock</p><p>Model 70</p><p>Serial 31370</p>

www.ebay.co.uk

Pics saved for posterity

View attachment 152227 View attachment 152226

Well spotted - nabbed it thanks, even if it's just to give it a good home. .

 

[s-band]

Well spotted - nabbed it thanks, even if it's just to give it a good home. .

There's a 2nd one Phantom Adjustable Bandpass Filter tuned to 70 MHz New Is Sealed Bag Boxed NOS | eBay
Can I resist? Probably.

 

[John]

There's a 2nd one Phantom Adjustable Bandpass Filter tuned to 70 MHz New Is Sealed Bag Boxed NOS | eBay
Can I resist? Probably.

Go on go on - worth a punt for £15

 

[Captain Jack]

For the stupid (me) - what would these be used for?

 

[s-band]

@Captain Jack Increasing the SNR on narrow analogue signals. Assuming the RX BW is 30MHz and your signal is around 7.5MHz wide, that's 1/4 of the BW. The noise will be reduced by the ratio of the BWs i.e. 1/4 which would be 6dB in theory. Hence 6dB increase in SNR, in theory. It used to work very well on some African C band stations but could result in loss of colour and other video problems. If you reduce the BW too much for the signal, you everything.

Tele Sahel on 1W 3913 RHCP SECAM with BW reduced to the max probably

 

[John]

For the stupid (me) - what would these be used for?

Your in good company CJ

 

[Captain Jack]

One for John to try definitely on the Brazilian analogue

 

[John]

One for John to try definitely on the Brazilian analogue

Yep that's the plan, and also do a performance comparison between my Echostar LT8700 in use now against other receivers but using an add-on 70MHz IF Loop filter

 

[satesco]

@Captain Jack ...

Tele Sahel on 1W 3913 RHCP SECAM with BW reduced to the max probably

View attachment 152243

Some analog receivers had a demodulation threshold so that you could see images. Still, the color disappeared, and the fleas were smaller, like in the second TeleSahel picture posted, if my visual memory serves me right.

 

[John]

These must be extremely rare now. They weren't that common way back. If anyone still has an analogue RX with 70MHz loop these are a must-have accessory @John

Phantom Adjustable Bandpass Filter tuned to 70 MHz New In Boxed NOS | eBay

<p>Phantom Adjustable Bandpass Filter tuned to 70 MHz New In Boxed NOS. </p><p>New old stock</p><p>Model 70</p><p>Serial 31370</p>

www.ebay.co.uk

Pics saved for posterity

View attachment 152227 View attachment 152226

I'll undress it when it gets here for your posterity folder

 

[Captain Jack]

I just looked on the back of the Chaparral Monterey receiver I have - and that has a 70MHz loop. Not sure if it has the threshold extension upgrade - would have been a good try for 70W.

 

[s-band]

Price in 1990 £75.04 + VAT
Sorry the scan is inverted

 

[Manikm909]

Price in 1990 £75.04 + VAT
Sorry the scan is inverted

man you could get some funky stuff back in the day!!!

 

[John]

Internals & info for the anoracks

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