Thinking about getting the Inrad 2.0 filter for my 817. Is it worth it? I was doing a SOTA today and noticed strong stations about 2khz away making it difficult on the frequency I was running on. Does anyone here have experience pre and post filter installed? I’ve also heard it can help improve TX filtering also…adding a little more punch with narrowing TX audio.
I realize sotabeams makes a DSP filter but not looking to do rig surgery etc. The Plugin inrad seemed like a good “upgrade” to me… but wondering the comments before I pull the trigger. Thanks!
I would say that depends very much on the price. I have seen they ask for about $140 per filter.
In times of radios with built in DSP that is too much.
Don’t get me wrong I really like my 817nd. It is a trusty companion but I would say saving the money makes more sense.
Or really simple just QSY a bit up or down and respot yourself. Chasers will follow along.
Your receiver IF is wider than it needs to be, so allows a nearby signal to be louder than you’d like albeit off-tuned.
The nearby signal is transmitting a wider signal than it should be, so the interference is actually in your receiver passband.
A narrower filter will help with the first problem, but will have no effect on problem 2.
If the INRAD filter is 2.0 khz wide, you’ll notice the impact on received signal quality immediately. The BFO injection frequency may well need to be adjusted in the level 2 menu, moving it closer to the filter on both sidebands (USB/LSB) and possibly on CW mode too if you use it - this adjustment would then affect how the receiver sounds with the standard filter, which may not matter if you used the narrow filter all the time. But against that, you’d be left with the standard 2.4-2.5ish filter on CW mode, possibly not a problem for you.
When you switch in the narrow filter, it is in action on transmit as well as receive. This increases the importance of resetting the BFO frequencies for each sideband as otherwise you’ll get reports of “thin” audio etc.
I have a Collins SSB filter for my 817 and one for CW too. I have installed the CW filter because it makes CW reception on a busy band quite enjoyable. There was an option offered by the W4RT club website whereby the ssb filter was permanently wired in where the ceramic filter usually is, and the cw filter was still optional on that mode. However the W4RT site seems to be inactive now.
I found that my stock 817nD was having same issue and then upgraded to the Collins YF-122s and that cleared up most the problem. And yes, it was pricey at around $160ish USD so it was not cheap. That was done for same reason of not wanting to do surgery on the radio. That filter did not require any fine tuning of the BFO injection frequencies and I do get good audio reports. Given comparable price for either the Yaesu/Collins or the Inrad as a fix, it’s really up to your price tolerance. Either one is better than the stock filter.
There are a couple of things you an try with an FT817 that cost nothing. They may help, but if they don’t, you still have the option of buying and installing a filter.
The first thing to try is the “IF Shift”. The instructions are on page 24 of the manual and enable you to move the existing filter band pass higher or lower (without changing the receive frequency the radio is tuned to), and so use the edge of the IF band-pass filter to remove an interfering signal that is close by.
The second thing to try is reducing the gain of the receiver by engaging the “IPO” function (essentially turning off the Rx pre-amp), engaging the “ATT” function (rx attenuator) and using the manual “RF gain” control (which is often disabled and use for a squelch function). This process is explained clearly in this U-tube video
Good luck, I would be interested to hear if either of these suggestions work for you,
Ian
VE6IXD
Thanks for all the tips and advise! I will try using the IF shift and IPO/ATT for now. $140 does seem steep for something that most on here are saying to QSY
